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