#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;
    n--;
    m--;
    if(n==0){
    cout<<m;
    }
    else if(m==0){
    cout<<n;
    }
    else{
    cout<<n*m;
    }
    return 0;
}