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


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