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