#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    int n,m;
    long long s;
    scanf("%d%d",&n,&m);
    if(n==1||m==1) s=n+m-2;
    else {
        s=n;
        s=s*(m-1);
        s--;
        s=s+n;
    }
    printf("%lld",s);
    return 0;
}