#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

void init (unsigned long int &p, unsigned long int &q);
int gcd (int a, int b);
int keySearch (int m);
bool prime(int checkNumber);
int getE (unsigned long int k);
int getD (unsigned long int k, unsigned long key);

int main (void) {
    unsigned long int p, q;

    init (p, q);
    if (p <= 0 || q <= 0 || p == q) {
        printf ("Wrong input!!!");
        return 1;
    }

    unsigned long int n = p * q;
    unsigned long int m = (p - 1) * (q - 1);
    unsigned long int keys = keySearch(m);
    unsigned long int e = getE(keys);
    unsigned long int d = getD(keys, e);
    unsigned long int openKey[2] = {e, n};
    unsigned long int secretKey[2] = {d, n};

    printf ("open exp 'e' = %ld\nsecret exp 'd' = %ld\n", e, d);

    char text [100];
    fgets (text, 99, stdin);
    puts (text);

    return 0;
}

void init (unsigned long int &p, unsigned long int &q) {
    printf ("enter first number: ");
    scanf ("%ld", &p);
    printf ("enter second number: ");
    scanf ("%ld", &q);
}

int gcd(int a, int b) {
   int c;
   while (b) {
      c = a % b;
      a = b;
      b = c;
   }
   return abs(a);
}

int keySearch(int m) {
    for (int i = 1; ; i++) {
        int sk = m * i + 1;
        for (int j = 2; j <= 5; j++)
            if ((sk % j == 0) && (sk / j != j) && (!prime(sk)))
                return sk;
    }
}

bool prime (int checkNumber) {
    for ( int i = 2; i * i <= checkNumber; i++ ) {
        if ( checkNumber % i == 0 ) {
            return false;
        }
    }
    return true;
}

int getE (unsigned long int k) {
    for (int i = 2; ; i++)
        if (k % i == 0)
            return i;
}

int getD (unsigned long int k, unsigned long int e) {
    return k / e;
}