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


int main() {
    long int rows, cols;
    cin >> rows;
    cin >> cols;
    
    long int result = (cols-1) + (rows-1)*cols;
    cout << result;
    
    return 0;
}