#include <bits/stdc++.h>
#define ll long long int

using namespace std;

int main(){
    ll n,m;
    cin>>n>>m;

    if (n<m)
        swap(n,m);

    ll ans1=n-1;

    ans1+=(n)*(m-1);

    ll ans2=m-1;
    ans2+=(m)*(n-1);

    cout<<min(ans1,ans2)<<endl;

}