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