#include <bits/stdc++.h>
using namespace std;
int n, a, b, c;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  cin >> a >> b >> c;
  if (n == 1)
    cout << "0";
  else
    cout << min(a, b) + (n - 2) * min(min(a, b), c);
}
