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