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