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


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