#include<bits/stdc++.h>
using namespace std;


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