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


int main() {
    long long n, m;
    cin>>n>>m;
    long long ans=m-1+m*1LL*(n-1);
    ans=min(ans, (long long)(n-1+n*1LL*(m-1)));
    cout << ans << endl;
}