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