Вычислительные системы и компьютерные сети

import base64
import math

def isPrime(n):
    d = 2
    while n % d != 0:
        d += 1
    return d == n
#



print("print P")
while True:
    p = int(input())
    if isPrime(p):
        print("P is prime")

        break
    else:
        print("P is not prime")

print("print Q")
while True:
    q = int(input())
    if isPrime(q):
        print("Q is prime")
        break
    else:
        print("Q is not prime")


n=p*q
phi=(q-1)*(p-1)
e= 7
# def egcd(a, b):
#     if a == 0:
#         return (b, 0, 1)
#     else:
#         g, x, y = egcd(b % a, a)
#         return (g, y - (b // a) * x, x)
#
#
# def mulinv(b, n):
#     g, x, _ = egcd(b, n)
#     if g == 1:
#         return x % n
d = 531

for i in range(1000):
    if i*e%phi==1:
        d = i
        break




print("Write a message")
message=input()
message_symbols = []
private_symbols=[]
decoded_message = []
for s in message:
    message_symbols.append(ord(s))

for o in message_symbols:
    l = o**e%n
    b = str(l).encode("UTF-8")
    private_symbols.append(b)

print(private_symbols)
for r in private_symbols:
    b = int(r.decode())

    l = b**d%n
    decoded_message.append(chr(l))

print(f"Decoded message: {''.join(decoded_message)}")