diff --git a/codec.hpp b/codec.hpp
new file mode 100644
index 0000000..db6b466
--- /dev/null
+++ b/codec.hpp
@@ -0,0 +1,221 @@
+#ifndef __LIB_CRYPTXX
+#define __LIB_CRYPTXX
+
+#include "lib.hpp"
+
+void BinaryOutput(FILE* fp, const char* str, long long len) {
+	for (long long i = 0; i < len; i++) {
+		putc(str[i], fp);
+	}
+}
+
+void ReadBytes(FILE* fp, char* str, long long len) {
+	for (long long i = 0; i < len; i++) {
+		str[i] = getc(fp);
+		// printf("NSG %d\n", ((unsigned char*)str)[i]);
+	}
+}
+
+#define charCodeAt(__ch, __pos) (unsigned char)((__ch >> (__pos << 3)) & 0xff)
+
+class EncodeArchive {
+private:
+	string f;
+	long long arcVersion;
+	string sourceFiles[65536];
+	long long ptrAt;
+	long long fileCount;
+	long long contentLengths[65536];
+	FILE *fp;
+	bool e;
+public:
+	EncodeArchive(string of) {
+		e = false;
+		f = of;
+		errno_t err = fopen_s(&fp, f.c_str(), "wb");
+		if (err) {
+			printf("Failed when opening the output file \"%s\", code %d.\n", f.c_str(), err);
+			e = true;
+		} else {
+			ptrAt = 0;
+			fileCount = 0;
+			arcVersion = CURRENT_VERSION;
+		}
+	}
+	void CreateHeader() {
+		BinaryOutput(fp, "LLAR\x00\x00\x00\x00\x0AMirekintoc", 19);
+		ptrAt += 19;
+	}
+	bool Error() {
+		return e;
+	}
+	void MakeTable() {
+		unsigned char ver[8];
+		for (int i = 0; i < fileCount; i++) {
+			for (int j = 7; j >= 0; j--) {
+				ver[7 - j] = charCodeAt(sourceFiles[i].length(), j);
+			}
+			BinaryOutput(fp, (char*)ver, 8);
+			BinaryOutput(fp, sourceFiles[i].c_str(), sourceFiles[i].length());
+			for (int j = 7; j >= 0; j--) {
+				ver[7 - j] = charCodeAt(contentLengths[i], j);
+			}
+			BinaryOutput(fp, (char*)ver, 8);
+			ptrAt += 16 + sourceFiles[i].length();
+		}
+		putc(0x7F, fp);
+		ptrAt++;
+	}
+	void AddFile(string f) {
+		printf("Adding file \"%s\"...\n", f.c_str());
+		sourceFiles[fileCount] = f;
+		contentLengths[fileCount] = gfsize(f.c_str());
+		if(contentLengths[fileCount] == -1) {
+			e = true;
+		}
+		fileCount++;
+	}
+	void ConstructFile() {
+		printf("Creating header...\n");
+		CreateHeader();
+		printf("Making table...\n");
+		MakeTable();
+		for (int i = 0; i < fileCount; i++) {
+			printf("Processing file \"%s\"...\n", sourceFiles[i].c_str());
+			FILE* f = fopen(sourceFiles[i].c_str(), "rb");
+			Mask0 msk;
+			msk.output_mask(fp);
+			msk.stream_encode(contentLengths[i], f, fp);
+			fclose(f);
+		}
+		printf("Done!\n");
+	}
+};
+
+class DecodeArchive {
+private:
+	string f;
+	long long contentLengths[65536];
+	long long beginAddr[65536];
+	string fileNames[65536];
+	long long headerLength, fileCount;
+	FILE *fp;
+	bool e;
+public:
+	DecodeArchive(string str) {
+		f = str;
+		char hdr[256];
+		e = false;
+		unsigned char* ref = (unsigned char*)hdr;
+		errno_t err = fopen_s(&fp, str.c_str(), "rb");
+		if (err) {
+			e = true;
+			printf("Failed when opening file \"%s\", code %d.\n", str.c_str(), err);
+		} else {
+			ReadBytes(fp, hdr, 4);
+			hdr[4] = 0;
+			string s = hdr;
+			if (s != "LLAR") {
+				e = true;
+				printf("File \"%s\" is not a valid LLAR file.\n", str.c_str());
+			} else {
+				int ver;
+				ReadBytes(fp, hdr, 4);
+				ver = (ref[0] << 24) + (ref[1] << 16) + (ref[2] << 8) + ref[3];
+				if (ver > 0) {
+					e = true;
+					printf("Unsupported file version %d\n", ver);
+				}
+			}
+		}
+	}
+	void GetInformations() {
+		char hdr[256];
+		unsigned char* ref = (unsigned char*)hdr;
+		ReadBytes(fp, hdr, 1);
+		int cop = hdr[0];
+		ReadBytes(fp, hdr, cop);
+		hdr[cop] = 0;
+		printf("Notice: This file is generated by %s\n", hdr);
+		headerLength = 9 + cop;
+		fileCount = 0;
+		while (true) {
+			ReadBytes(fp, hdr, 1);
+			if (hdr[0] == 0x7F) {
+				break;
+			}
+			ReadBytes(fp, hdr + 1, 7);
+			long long nl = 0;
+			for (int i = 0; i < 8; i++) {
+				nl |= ref[i] << ((7 - i) << 3);
+				// printf("ADD %lld %d %d\n", ref[i] << ((7 - i) << 3), hdr[i], ref[i]);
+			}
+			ReadBytes(fp, hdr, nl);
+			hdr[nl] = 0;
+			printf("New file got: \"%s\"\n", hdr);
+			fileNames[fileCount] = hdr;
+			ReadBytes(fp, hdr, 8);
+			contentLengths[fileCount] = 0;
+			for (int i = 0; i < 8; i++) {
+				contentLengths[fileCount] |= ref[i] << ((7 - i) << 3);
+			}
+			headerLength += 16 + nl;
+			fileCount++;
+		}
+		headerLength++;
+		long long ptrAt = headerLength;
+		for (int i = 0; i < fileCount; i++) {
+			beginAddr[i] = ptrAt;
+			ptrAt += contentLengths[i] + 256;
+		}
+	}
+	bool Error() {
+		return e;
+	}
+	void ExtractEach(string str) {
+		printf("Extracting \"%s\"...\n", str.c_str());
+		int id = -1;
+		for (int i = 0; i < fileCount; i++) {
+			if (fileNames[i] == str) {
+				id = i;
+				break;
+			}
+		}
+		if (!~id) {
+			printf("Cannot find file \"%s\" in archive \"%s\".\n", str, f);
+			e = true;
+			return;
+		}
+		FILE *f1;
+		errno_t err = fopen_s(&f1, str.c_str(), "wb");
+		if (err) {
+			printf("Failed when opening file \"%s\", code %d.\n", str, err);
+			e = true;
+			return;
+		}
+		int err1 = _fseeki64(fp, beginAddr[id], SEEK_SET);
+		if (err1) {
+			printf("Failed when moving cursor in \"%s\", code %d.\n", str, err1);
+		}
+		Mask0 msk(fp);
+		msk.stream_decode(contentLengths[id], fp, f1);
+		fclose(f1);
+	}
+	void ExtractAll() {
+		FILE* f1;
+		for (int i = 0; i < fileCount; i++) {
+			printf("Extracting \"%s\"...\n", fileNames[i].c_str());
+			errno_t err = fopen_s(&f1, fileNames[i].c_str(), "wb");
+			if (err) {
+				printf("Failed when opening file \"%s\", code %d.\n", fileNames[i], err);
+				e = true;
+				return;
+			}
+			Mask0 msk(fp);
+			msk.stream_decode(contentLengths[i], fp, f1);
+			fclose(f1);
+		}
+	}
+};
+
+#endif
\ No newline at end of file
diff --git a/compile.bat b/compile.bat
new file mode 100644
index 0000000..b44cf76
--- /dev/null
+++ b/compile.bat
@@ -0,0 +1,12 @@
+@echo off
+
+setlocal
+
+cd /d %~dp0
+echo Compiling 'llarm.cpp' into 'llarm.exe'...
+g++ llarm.cpp -O2 -static -Wl,--stack=256000000 -o llarm.exe
+echo Compiling 'simpllar.cpp' into 'simpllar.exe'...
+g++ simpllar.cpp -O2 -static -Wl,--stack=256000000 -o simpllar.exe
+echo Done!
+
+endlocal
diff --git a/lib.hpp b/lib.hpp
new file mode 100644
index 0000000..c5b1afb
--- /dev/null
+++ b/lib.hpp
@@ -0,0 +1,97 @@
+#ifndef __LIB_CRYPT
+#define __LIB_CRYPT
+
+#define CURRENT_VERSION 0
+
+#include <bits/stdc++.h>
+using namespace std;
+
+mt19937 rnd;
+
+void Init() {
+	rnd.seed(random_device{}());
+}
+
+class Mask0 {
+private:
+	unsigned char conv[256], dconv[256];
+public:
+	Mask0() {
+		bool vis[258];
+		memset(vis, 0, sizeof(vis));
+		int nex, cnt, cur;
+		for (int i = 0; i < 256; i++) {
+			nex = rnd() % (256 - i);
+			cnt = 0;
+			cur = 0;
+			while (cnt <= nex) {
+				if (!vis[cur]) {
+					cnt++;
+				}
+				cur++;
+			}
+			conv[i] = cur - 1;
+			vis[cur - 1] = true;
+		}
+		for (int i = 0; i < 256; i++) {
+			dconv[conv[i]] = i;
+		}
+	}
+	Mask0(FILE *s) {
+		for (int i = 0; i < 256; i++) {
+			conv[i] = getc(s);
+		}
+		for (int i = 0; i < 256; i++) {
+			dconv[conv[i]] = i;
+		}
+	}
+	void output_mask(FILE* out) {
+		for (int i = 0; i < 256; i++) {
+			putc(conv[i], out);
+		}
+	}
+	void stream_encode(long long content_length, FILE* in, FILE* out) {
+		unsigned char ch, xorbase = 0;
+		for (long long i = 0; i < content_length; i++) {
+			ch = getc(in);
+			xorbase ^= ch;
+			putc(conv[xorbase], out);
+		}
+	}
+	void stream_decode(long long content_length, FILE* in, FILE* out) {
+		unsigned char ch, prev = conv[0];
+		for (long long i = 0; i < content_length; i++) {
+			ch = getc(in);
+			putc(dconv[prev] ^ dconv[ch], out);
+			prev = ch;
+		}
+	}
+};
+
+long long gfsize(const char *fn) {
+	if (!fn) {
+		return -1;
+	}
+	FILE *fp = NULL;
+	long long res;
+	errno_t err0 = fopen_s(&fp, fn, "rb");
+	if (err0 != 0) {
+		printf("Failed when opening file \"%s\", code %d.\n", fn, err0);
+		return -1;
+	}
+	int err1 = _fseeki64(fp, 0, SEEK_END);
+	if (err1 != 0) {
+		printf("Failed when moving cursor in file \"%s\" (SEEK_END), code %d.\n", fn, err1);
+		return -1;
+	}
+	res = _ftelli64(fp);
+	int err2 = _fseeki64(fp, 0, SEEK_SET);
+	if (err2 != 0) {
+		printf("Failed when moving cursor in file \"%s\" (SEEK_SET), code %d.\n", fn, err1);
+		return -1;
+	}
+	fclose(fp);
+	return res;
+}
+
+#endif
\ No newline at end of file
diff --git a/llarm.cpp b/llarm.cpp
new file mode 100644
index 0000000..9da2729
--- /dev/null
+++ b/llarm.cpp
@@ -0,0 +1,86 @@
+#include "codec.hpp"
+
+void About() {
+	puts("Mirekintoc's LLAR CLI v1.0.0");
+	puts("Designed for LLAR v1.0");
+	puts("LLAR (MOS-0001) is a definition, not a project.");
+	puts("Join the MOS (Mirekintoc Open Standards)!");
+	puts("Copyright(C) 2009-2023 Mirekintoc Void.");
+	puts("Copyright(C) 2019-2023 Minphtis Development.");
+	puts("Under MIT License.");
+}
+
+void Help() {
+	puts("Usage:");
+	puts("llarm <archive> [d|e] <optional: files>\n");
+	puts("Use \'d\' to decode a file.");
+	puts("If you used <optional: files>, than it will");
+	puts("do not extract all files, but decode files");
+	puts("mentioned. You can use it for not only once.\n");
+	puts("Use \'e\' to encode a file.");
+	puts("If you do not used <optional: files>, than it");
+	puts("will be an empty archive. Just contain something");
+	puts("in it!\n");
+	puts("\"llarm -h|--help\" will show help.");
+	puts("\"llarm -a|--about\" will show about.");
+}
+
+int main(int argc, char *argv[]) {
+	Init();
+	if (argc == 1) {
+		About();
+		putchar('\n');
+		Help();
+		return 0;
+	}
+	if (argc == 2) {
+		string argv_1 = argv[1];
+		if (argv_1 == "-h" || argv_1 == "--help") {
+			Help();
+			return 0;
+		}
+		if (argv_1 == "-a" || argv_1 == "--about") {
+			About();
+			return 0;
+		}
+		puts("Unknown usage!\n");
+		Help();
+		return 1;
+	}
+	string f = argv[1], opt = argv[2];
+	if (opt == "d") {
+		DecodeArchive darch(f);
+		if (darch.Error()) {
+			return 1;
+		}
+		darch.GetInformations();
+		if (argc > 3) {
+			for (int i = 3; i < argc; i++) {
+				darch.ExtractEach(argv[i]);
+				if (darch.Error()) {
+					return 1;
+				}
+			}
+		} else {
+			darch.ExtractAll();
+		}
+		return darch.Error();
+	}
+	if (opt == "e") {
+		EncodeArchive earch(f);
+		if (earch.Error()) {
+			return 1;
+		}
+		for (int i = 3; i < argc; i++) {
+			earch.AddFile(argv[i]);
+			if(earch.Error()) {
+				return 1;
+			}
+		}
+		earch.ConstructFile();
+		return earch.Error();
+	}
+	puts("Unknown operation!");
+	Help();
+	return 1;
+}
\ No newline at end of file
diff --git a/simpllar.cpp b/simpllar.cpp
new file mode 100644
index 0000000..60746dd
--- /dev/null
+++ b/simpllar.cpp
@@ -0,0 +1,73 @@
+#include "codec.hpp"
+
+string fnproc(string fn) {
+	string ret = "", tmp = "";
+	int len = fn.length();
+	for (int i = 0; i < len; i++) {
+		if (fn[i] == '.') {
+			ret += tmp;
+			tmp = ".";
+		} else {
+			tmp += fn[i];
+		}
+	}
+	if (ret == "") {
+		ret = tmp;
+	}
+	ret += ".llar";
+	return ret;
+}
+
+string getext(string fn) {
+	string res = "";
+	int len = fn.length();
+	for (int i = 0; i < len; i++) {
+		if (fn[i] == '.') {
+			res = "";
+		} else {
+			res += fn[i];
+		}
+	}
+	return res;
+}
+
+int main(int argc, char *argv[]) {
+	Init();
+	if (argc == 1) {
+		return 0;
+	}
+	if (argc == 2) {
+		if (getext(argv[1]) == "llar") {
+			DecodeArchive darch(argv[1]);
+			if (darch.Error()) {
+				return -1;
+			}
+			darch.GetInformations();
+			darch.ExtractAll();
+			return darch.Error();
+		} else {
+			EncodeArchive earch(fnproc(argv[1]));
+			if (earch.Error()) {
+				return 1;
+			}
+			earch.AddFile(argv[1]);
+			if(earch.Error()) {
+				return 1;
+			}
+			earch.ConstructFile();
+			return earch.Error();
+		}
+	}
+	EncodeArchive earch("out.llar");
+	if (earch.Error()) {
+		return 1;
+	}
+	for (int i = 1; i < argc; i++) {
+		earch.AddFile(argv[i]);
+		if(earch.Error()) {
+			return 1;
+		}
+	}
+	earch.ConstructFile();
+	return earch.Error();
+}
\ No newline at end of file