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


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