#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
  int N,A,B;
  cin>>N>>A>>B;
  int ans = A*(N-1)-B*N;
  if(N%2 == 0){
      ans = min({ans,-A*(N-1),-A*(N-3)-B*2});
  }
  else{
      ans = min(ans,-A*(N-1)-B);
  }
  cout<<ans<<endl;
}