GreatestCommonDivisor.java

import java.util.Scanner;

public class GreatestCommonDivisor {

    public static int gcd_naive(int a, int b) {

        if (b == 0)
            return a;

        return gcd_naive(b, a % b);

    }

    public static void main(String args[]) {

        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        int b = scanner.nextInt();
        scanner.close();

        System.out.println(gcd_naive(a, b));
    }
}