#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  map<int, int> M;
  int a;
  long long sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> a;
    sum += a;
    if (M.find(a) != M.end()) {
      M[a]++;
    } else {
      M[a] = 1;
    }
  }
  bool flag = 0;
  if (M.find(0) != M.end() && (M.find(0))->second > 1) {
    flag = 1;
  } else {
    int k = 0;
    for (map<int, int>::iterator it = M.begin(); it != M.end(); it++) {
      if (it->second >= 2) {
        k++;
      }
      if (it->second > 2) {
        flag = 1;
        break;
      }
    }
    if (k > 1) {
      flag = 1;
    }
    if (!flag) {
      if (M.find(0) != M.end() && M.find(1) != M.end() &&
          M.find(1)->second > 1) {
        flag = 1;
      } else {
        for (map<int, int>::iterator it = M.begin(); it != M.end(); it++) {
          if (it->second == 2 && M.find(it->first - 1) != M.end()) {
            flag = 1;
            break;
          }
        }
        if (!flag) {
          long long d = sum - 1ll * (n - 1) * n / 2;
          flag = !(d % 2);
        }
      }
    }
  }
  if (!flag)
    cout << "sjfnb";
  else
    cout << "cslnb";
  return 0;
}
