#include <bits/stdc++.h>
#define ll long long
using namespace std;
int main(){
    ll n,m,mn,mx;
    cin>>n>>m;
    mn=min(m,n);
    mx=max(m,n);
    ll ans1=mx-1+(mn-1)*mx;
    ll ans2=mn-1+(mx-1)*mn;
    cout<<min(ans1,ans2)<<endl;
}