#include <bits/stdc++.h>
using namespace std;
long long nc2(int n) { return n * 1ll * (n - 1) / 2; }
string solve() {
  string p[2] = {"cslnb", "sjfnb"};
  int n, cnt = 0;
  cin >> n;
  long long sum = 0;
  vector<long long> arr(n);
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    sum += arr[i];
  }
  sort(arr.begin(), arr.end());
  for (int i = 0; i < n; i++)
    if (arr[i] < i) return p[0];
  for (int i = 1; i < n; i++) cnt += (arr[i - 1] == arr[i]);
  for (int i = 1; i < n - 1; i++)
    if (arr[i] - arr[i - 1] == 1 && arr[i] == arr[i + 1]) return p[0];
  if (cnt > 1) return p[0];
  return p[(sum - nc2(n)) % 2];
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cout << solve() << "\n";
  return 0;
}
