#include <bits/stdc++.h>
using namespace std;
using ll = long long;
bool solve() {
  int N;
  cin >> N;
  vector<int> a(N);
  for (int i = 0; i < N; ++i) cin >> a[i];
  sort(a.begin(), a.end());
  map<int, int> ma;
  for (int i = 0; i < N; ++i) {
    ma[a[i]]++;
    if (ma[a[i]] > 2)
      return false;
    else if (ma[a[i]] > 1 && ma[a[i] - 1] > 0)
      return false;
    else if (a[i] == 0 && ma[a[i]] > 1)
      return false;
  }
  int cnt = 0;
  for (auto p : ma) {
    if (cnt <= p.second) {
      if (cnt > 1 && p.second > 1) return false;
      cnt = p.second;
    }
  }
  ll sum = 0;
  int n = 0;
  for (int i = 0; i < N; ++i) {
    if (a[i] - n >= 0) {
      sum += a[i] - n;
      n++;
    }
  }
  return sum % 2;
}
int main() {
  cout << (solve() ? "sjfnb" : "cslnb") << endl;
  return 0;
}
