#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,d,s;
    cin>>n>>m;
    d=m-1;
    s=(n-1)*m;
    cout<<(d+s)<<endl;
    return 0;
}