#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  int n;
  while (cin >> n) {
    cin >> a >> b >> c;
    if (n == 1) {
      cout << "0" << endl;
      continue;
    }
    if (n == 2) {
      cout << min(a, b) << endl;
      continue;
    }
    if (n >= 3) {
      int temp = min(a, b);
      if (c < temp) {
        cout << min(a, b) + c * (n - 2) << endl;
      } else {
        cout << min(a, b) * (n - 1) << endl;
      }
    }
  }
  return 0;
}
