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