#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 int n;
    cin>>n;
    long long int m;
    cin>>m;
    if(m==n==1)
        cout<<"1";
    else if(m==1 && n>1)
        cout<<n-1;
    else if(n==1 && m>1)
        cout<<m-1;
    else
        cout<<(n*m)-1;
        
    return 0;
}