#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;
    long long j=max(m,n);
    long long k=min(m,n);
    
    if(k==1)cout<<j-1;
    else
    cout<<min(j-1+j*(k-1),k-1+k*(j-1));
    return 0;
}