멀쩡한 사각형 (자바)

package prog;

public class 멀쩡한_사각형 {
    public static void main(String[] args) {
        Solution_멀쩡한_사각형 s = new Solution_멀쩡한_사각형();
        System.out.println(s.solution(8	,12));
        System.out.println(s.solution(2	,3));
    }
}
class Solution_멀쩡한_사각형{
    public long solution(int w, int h) {
        long answer = 1;
        answer=(long)w*h - (w+h-gcd(w,h));
        return answer;
    }

    public static int gcd(int a, int b) {
        while(b!=0){
            int r = a%b;
            a= b;
            b= r;
        }
        return a;
    }



}