import string


def encryption(msg):
    ct = []
    for char in msg:
        ct.append((123 * ord(char) + 18) % 256)
    return bytes(ct)

dict = {}

for elem in string.printable:
    enc = encryption(elem)[0]
    dict[elem] = enc
    dict[enc] = elem

print(dict)

f = open('./msg.enc','r')
ct = f.readline()
ct = [int(ct[i:i+2],16) for i in range(0, len(ct), 2)]

solve = ""
for elem in ct:
    solve += dict[elem]

print(solve)