#include <bits/stdc++.h>
using namespace std;
long long modpow(long long a, long long b,
                 long long mod = (long long)(1e9 + 7)) {
  if (!b) return 1;
  a %= mod;
  return modpow(a * a % mod, b / 2, mod) * (b & 1 ? a : 1) % mod;
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int mxn = 1e5 + 1;
long long n, ele, ope;
int mx, ct, below;
long long pile[mxn];
map<long long, int> cnt;
int solution() {
  if (cnt[0] > 1 || mx || ct > 1 || below) {
    return 0;
  }
  long long num = 0;
  for (int i = 0; i < n; i++) {
    num += pile[i] - i;
  }
  cerr << num << endl;
  return (num) % 2;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  scanf("%lli", &n);
  for (int i = 0; i < n; i++) {
    scanf("%lli", &pile[i]);
  }
  sort(pile, pile + n);
  for (int i = 0; i < n; i++) {
    cnt[pile[i]]++;
    if (cnt[pile[i]] > 2)
      mx = 1;
    else if (cnt[pile[i]] > 1)
      ct++;
    if (cnt[pile[i]] > 1 && pile[i] > 0 && cnt[pile[i] - 1]) below++;
  }
  string ans = solution() ? "sjfnb" : "cslnb";
  cout << ans << endl;
  return 0;
}
