#include<iostream>
#include<math.h>
#include<string>

using namespace std;

int gcd(int n,int m)
{
    if(m<=n && n%m ==0)
        return m;
    if(n<m)
        return gcd(m,n);
    else
        return gcd(m,n%m);
}

int REncryptText(char m)
{


    int p = 11, q = 3;
    int e = 3;
    int n = p * q;
    int phi = (p - 1) * (q - 1);

    int check1 = gcd(e, p - 1);
    int check2 = gcd(e, q - 1);

    int check3 = gcd(e, phi);

    //     // Compute d such that ed = 1 (mod phi)
    //i.e. compute d = e-1 mod phi = 3-1 mod 20
    //i.e. find a value for d such that phi divides (ed-1)
    //i.e. find d such that 20 divides 3d-1.
    //Simple testing (d = 1, 2, ...) gives d = 7

    //   double d = Math.Pow(e, -1) % phi;

    int d = 7;

    // public key = (n,e) // (33,3)
    //private key = (n,d) //(33 ,7)

    double g = pow(m,e);
    int ciphertext = g %n;
    // Now say we want to encrypt the message m = 7, c = me mod n = 73 mod 33 = 343 mod 33 = 13. Hence the ciphertext c = 13.

    //double decrypt = Math.Pow(ciphertext, d) % n;
    return ciphertext;
}

int main()
{
    char plaintext[80],str[80];

    cout<<" enter the text you want to encrpt";
    cin.get(plaintext,79);

    int l =strlen(plaintext);
    for ( int i =0 ; i<l ; i++)
    {
        char s = plaintext[i];
        str[i]=REncryptText(s);
    }

    for ( int i =0 ; i<l ; i++)
    {
        cout<<"the encryption of string"<<endl;
        cout<<str[i];
    }


    return 0;
}