#include <bits/stdc++.h>
#define ll unsigned long long
using namespace std;
int main()
{
  // freopen("in.txt","r",stdin);
   ll n,m;
   cin>>n>>m;
   
   cout<<min(m-1+m*1LL*(n-1) , (n-1)+ n*1LL*(m-1) )<<endl;
     return 0;
}