#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 long n,m;
    cin>>n>>m;
    if(n!=1 && m!=1){
        cout<<(n-1)*(m-1);
    }
    else{
        if(n==1){
            cout<<(m-1);
        }
        else{
            cout<<(n-1);
        }
    }
    return 0;
}