#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 n,m;
    cin>>n>>m;
    if(n==1 || m==1)
        {
        cout<<n+m-2;
        return 0;
    }
    else{
        long mn=min(n,m)-1;
        long mx=max(n,m)-1;
        long ans=mn+(mn+1)*mx;
        cout<<ans;
    }
    return 0;
}