#include <bits/stdc++.h>
using namespace std;
const long long MAXN = 1e6 + 10;
const long long INF = 1e9 + 10;
const int MOD = 998244353;
int n, a[MAXN];
map<int, int> cnt;
set<int> st;
void scnd() {
  cout << "cslnb";
  exit(0);
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    cnt[a[i]]++;
    st.insert(a[i]);
  }
  bool check = 0;
  for (auto x : st) {
    if (cnt[x] > 2) scnd();
    if (cnt[x] == 2) {
      if (check || cnt[x - 1] > 0 || x == 0) scnd();
      check = 1;
    }
  }
  sort(a, a + n);
  long long sum = 0;
  for (int i = 0; i < n; i++) sum += (long long)(a[i] - i);
  if (sum % 2 == 0) scnd();
  cout << "sjfnb";
  return 0;
}
