#include <stdio.h>

long power_mod(long base, long exp, long mod) {
  long result = 1;
  base = base % mod;
  while (exp > 0) {
    if (exp % 2 == 1) result = (result * base) % mod;
    base = (base * base) % mod;
    exp = exp / 2;
  }
  return result;
}

int main() {
  long m = 65;
  long e = 17, n = 3233;
  long c = power_mod(m, e, n);
  printf("ciphertext = %ld\n", c);
  long d = 2753;
  long back = power_mod(c, d, n);
  printf("plaintext  = %ld\n", back);
  return 0;
}