#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  int n;
  cin >> n >> a >> b >> c;
  if (n == 1) {
    cout << "0" << endl;
  } else if (n == 2) {
    cout << min(a, b) << endl;
  } else {
    if (c >= a || c >= b) {
      printf("%d\n", (n - 1) * min(a, b));
    } else if (a >= c && b >= c) {
      printf("%d\n", min(a, b) + (n - 2) * c);
    }
  }
  return 0;
}
