#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 */
    unsigned long long int n, m;
    std::cin >> n >> m;
    
    unsigned long long int cuts = (n -1) * m + (m -1);
    std::cout << cuts << std::endl;
    return 0;
}