#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    long n,m;
    cin>>n>>m;
    
    /*if(n>m){
        ans+=m+n-2;
    }
    else{
        
    
    }*/
    cout<<m*n-1;
    return 0;
}