#include <bits/stdc++.h>
using namespace std;
void winner(bool first) {
  if (first) {
    cout << "sjfnb";
  } else {
    cout << "cslnb";
  }
  exit(0);
}
int main() {
  long long n;
  cin >> n;
  vector<long long> a(n);
  map<int, int> m;
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    m[a[i]]++;
  }
  int count = 0;
  for (auto iter = m.begin(); iter != m.end(); ++iter) {
    if (iter->second > 2) {
      winner(false);
    }
    if (iter->second > 1) {
      ++count;
      if (m.count(iter->first - 1) || iter->first == 0) {
        winner(false);
      }
    }
  }
  if (count > 1) {
    winner(false);
  }
  sort(a.begin(), a.end());
  bool first_turn = true;
  for (int i = 0; i < a.size(); ++i) {
    first_turn = (a[i] - i) % 2 == 0 ? first_turn : !first_turn;
  }
  winner(!first_turn);
  return 0;
}
