#include <bits/stdc++.h>
using namespace std;
void debug() { cerr << "\n"; }
template <typename Head, typename... Tail>
void debug(Head a, Tail... b) {
  cerr << a << " ";
  debug(b...);
}
template <class T>
void umin(T &a, T b) {
  a = min(a, b);
}
template <class T>
void umax(T &a, T b) {
  a = max(a, b);
}
const int mod = 1e9 + 7, N = 1e6 + 5;
void solve() {
  int n, a, b, c;
  cin >> n >> a >> b >> c;
  int need = n - 1;
  int ans = 0;
  int cur = 1;
  while (need--) {
    if (cur == 1) {
      if (a < b) {
        cur = 2;
        ans += a;
      } else
        cur = 3, ans += b;
    } else if (cur == 2) {
      if (a < c) {
        cur = 1;
        ans += a;
      } else
        cur = 3, ans += c;
    } else if (cur == 3) {
      if (b < c) {
        cur = 1;
        ans += b;
      } else {
        cur = 2;
        ans += c;
      }
    }
  }
  cout << ans;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int T = 1;
  while (T--) solve();
}
