0.辗转相除法

package hello;

import java.util.Scanner;

public class Main {

    public static void main(String[], args) {
        Scanner in = new Scanner(System.in);
            int a=in.nextInt();    
            int b=in.nextInt();
            while(b!=0) {
                int r=a%b;
                a=b;
                b=r;
            }
    }     
}