#include <iostream>

using namespace std;
int gcd(int a, int b){
    if (b==0){
    return a;
}
return gcd (b,a%b);
}
int lcm (int a,int b) {
return (a*b)/gcd(a,b);

}
int main () {

    int a,b;
    cout << "Enter [a] : ";
    cin >> a;
    cout << "Enter [b] : ";
    cin >> b;


    int g = gcd(a, b);
    cout << "GCD  of a and b is: "<< g;





}