#include <bits/stdc++.h>
using namespace std;
const int limit = 1000000;
void die() {
  cout << "cslnb" << endl;
  exit(0);
}
long long int n;
int v[limit];
void check() {
  int i = 0;
  while (i < n - 1 and v[i] < v[i + 1]) i++;
  if (i >= n - 1) return;
  if (i == 0 and v[i] == 0) die();
  if (0 < i and v[i - 1] + 1 == v[i]) die();
  if (i < n - 2 and v[i] == v[i + 2]) die();
  i += 2;
  while (i < n - 1 and v[i] < v[i + 1]) i++;
  if (i >= n - 1) return;
  die();
}
long long int sum;
long long int moves;
int main() {
  ios::sync_with_stdio(false);
  cin >> n;
  for (int i = 0; i < n; i++) cin >> v[i];
  sort(v, v + n);
  check();
  for (int i = 0; i < n; i++) sum += v[i];
  moves = sum - n * (n - 1) / 2;
  if (moves % 2 == 0) die();
  cout << "sjfnb" << endl;
}
