#include <iostream>
int main() {
    long n, m;
    std::cin >> n >> m;
    long hotdog    = n -1;
    long hamburger = m -1;
    hotdog += n * (m-1);
    hamburger += m * (n-1);
    long min = hotdog < hamburger ? hotdog : hamburger;
    std::cout << min << std::endl;
}