#include <iostream>
#include <cmath>
using namespace std;

bool checkPrime(int prime);

int main() {
    int prime = 0;
    cout << "Enter a number" << endl;
    cin >> prime;
    bool isPrime = checkPrime(prime);
    if(isPrime == 1)
      cout << "It's a prime number" << endl;
    else
      cout << "It isn't a prime number" << endl;

    return 0;
}

bool checkPrime(int prime) {
    int isPrime = prime % 2;
    if(isPrime == 1)
      return 1;
    else
      return 0;
}