#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
#define lli long long int

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    lli a,b;
    cin>>a>>b;
    if(a==1)
        cout<<b-1<<endl;
    else if(b==1)
        cout<<a-1<<endl;
    else
        cout<<(min((a-1)*(b)+(b-1),(b-1)*(a)+(a-1)))<<endl;
    return 0;
}