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


int main() {
    long long n , m ;
    cin >> n >> m ;
    if(n>m)swap(n,m);
    cout << (n-1ll)+(m-1ll)*(n);
    return 0;
}