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


int main() {
    long long int n,m,ans1,ans2;
    cin>>n>>m;
    ans1 = (n-1)+n*(m-1);
    ans2= (m-1) + m*(n-1);
    cout<<max(ans1,ans2);
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}