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