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