public class GreatestCommonDivisor {

    public static void main(String[] args){
        int n1 = 50,n2 = 25;
        int gcd = gcd(n1,n2);

        System.out.printf("G.C.D of %d and %d is %d.",n1,n2,gcd);
    }

    public static int gcd(int n1, int n2){
        if(n2 == 0)
            return n1;
        else
            return gcd(n2,n1%n2);
    }

}