#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 */  
    long long n,m; cin >> n >>m;
    
   
    long long ans = n - 1;
    
    ans += (m - 1)*n;
    
    cout << ans;
    return 0;
}