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