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