diff --git a/lesson_2/Lession_2.py b/lesson_2/Lession_2.py
new file mode 100644
index 0000000..0c57817
--- /dev/null
+++ b/lesson_2/Lession_2.py
@@ -0,0 +1,36 @@
+import math
+import sys
+
+if not (2 <= len(sys.argv) <= 3):
+    print('Usage: python', sys.argv[0], 'input_file')
+    exit(-1)
+
+with open(sys.argv[1],'rb') as file:
+    data = file.read()
+
+outpath = sys.argv[2] if len(sys.argv) == 3 else sys.argv[1] + '.txt'
+dictionary = {i: (i,) for i in range(256)}
+sequence = list()
+i = 0
+
+with open(outpath, 'wb') as file:
+    while i < len(data):
+        if len(sequence) == 0:
+            n = len(dictionary)
+        else:
+            n = len(dictionary) + 1
+        nbits = math.ceil(math.log2(n))
+        if nbits % 8 == 0:
+            nbytes = nbits // 8
+        else:
+            nbytes = nbits // 8 + 1
+        Slice = data[i:i + nbytes]
+        index = int.from_bytes(Slice, 'little')
+        if index == len(dictionary):
+            new_sequence = sequence + sequence[-1:]
+        else:
+            new_sequence = list(dictionary[index])
+        file.write(bytearray(new_sequence))
+        dictionary[len(dictionary)] = tuple(sequence + new_sequence[-1:])
+        i += nbytes
+        sequence = new_sequence