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