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