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