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