#include <bits/stdc++.h>
using namespace std;
int main() {
  int d;
  int n;
  string a = "sjfnb", b = "cslnb";
  cin >> n;
  int A[n];
  for (int i = 0; i < n; i++) cin >> A[i];
  if (n == 1) {
    if (A[0] & 1) {
      cout << a << endl;
    } else
      cout << b << endl;
    return 0;
  }
  sort(A, A + n);
  int nb = 0;
  int save = -1;
  for (int i = 0; i < n - 1; i++) {
    if (A[i] == A[i + 1]) save = i, nb++;
  }
  if (nb > 1 || A[0] == A[1] && A[0] == 0) {
    cout << b << endl;
    return 0;
  }
  if (nb == 1) {
    if (A[save] == save) {
      cout << b << endl;
      return 0;
    }
    if (save > 0) {
      if (A[save - 1] + 1 == A[save]) {
        cout << b << endl;
        return 0;
      }
    }
  }
  long long cp = 0;
  for (int i = 0; i < n; i++) {
    cp += A[i] - i;
  }
  if (cp & 1) {
    cout << a << endl;
  } else
    cout << b << endl;
  return 0;
}
