#include <bits/stdc++.h>
using namespace std;
const int Nmax = 1e5 + 5;
long long v[Nmax];
int main() {
  ios_base ::sync_with_stdio(false);
  cin.tie(nullptr);
  mt19937 rng(chrono::steady_clock ::now().time_since_epoch().count());
  uniform_int_distribution<int> _random(1, INT_MAX);
  int n;
  cin >> n;
  map<int, int> M;
  long long sum = 0;
  for (int first, i = 1; i <= n; ++i) {
    cin >> first;
    v[i] = first;
    ++M[first];
  }
  string s1 = "sjfnb";
  string s2 = "cslnb";
  if (M[0] > 1) {
    cout << s2;
    return 0;
  }
  int nr = 0;
  for (auto &it : M) {
    if (it.second > 2) {
      cout << s2;
      return 0;
    }
    if (it.second > 1 and M[it.first - 1] > 0) {
      cout << s2;
      return 0;
    }
    if (it.second > 1) ++nr;
  }
  if (nr > 1) {
    cout << s2;
    return 0;
  }
  sort(v + 1, v + n + 1);
  for (int i = 1; i <= n; ++i) {
    sum += (v[i] - i + 1);
  }
  if (sum & 1LL)
    cout << s1;
  else
    cout << s2;
  return 0;
}
