#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    long long m,n,r;
    cin>>n>>m;
    if(n==1||m==1)
        {
        if(n==1)
            cout<<m-1;
        else 
            cout<<n-1;
    }
    else
        cout<<(m-1)+((n-1)*m);
    return 0;
}