#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#define ll long long int
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    ll N,M;
    cin >> N >> M;
    ll K = min(N,M);
    ll P = max(N,M);
    cout << min((K-1)+(K*(P-1)),(P-1)+(P*(K-1))) <<endl;
    return 0;
}