#include <bits/stdc++.h>
using namespace std;
const int maxn = 10003;
int32_t main() {
  int n, a, b, c;
  cin >> n >> a >> b >> c;
  if (n == 1) {
    cout << "0";
    return 0;
  }
  n--;
  long long ans = 0;
  ans += min(a, b);
  n--;
  if (min(a, b) > c) {
    ans += n * c;
    cout << ans;
    return 0;
  }
  ans += n * min(a, b);
  cout << ans;
  return 0;
}
