#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 i, j,k;
    cin >> i >> j;
    k=(i-1)+((j-1)*i);
    cout << k;
    return 0;
}