#include <bits/stdc++.h>
using namespace std;
const int MAX = 1e5 + 10;
int a[MAX];
int main() {
  int n;
  cin >> n;
  map<int, int> mp;
  int ok = 1;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    mp[a[i]]++;
    ok &= (mp[a[i]] < 3);
  }
  int cnt = 0;
  for (auto it : mp) {
    if (it.second >= 2) cnt++;
  }
  ok &= (cnt <= 1);
  for (auto it : mp) {
    if (it.second == 2) {
      ok &= (mp.count(it.first - 1) == 0);
      if (it.first == 0) ok = 0;
    }
  }
  if (!ok) return 0 * puts("cslnb");
  sort(a + 1, a + 1 + n);
  long long s = 0;
  for (int i = 1; i <= n; i++) {
    assert(a[i] >= i - 1);
    s += a[i] - (i - 1);
  }
  s %= 2;
  return 0 * puts(s ? "sjfnb" : "cslnb");
}
