#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
long long int maxi(long long int a,long long int b)
    {
    if(a<b)
        {
        return a;
    }
    else
        {
        return b;
    }
}

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