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