#include <bits/stdc++.h>
using namespace std;
void lose() { cout << "cslnb\n"; }
void win() { cout << "sjfnb\n"; }
long long cntMoves(vector<long long> &p) {
  sort(p.begin(), p.end());
  long long ans = 0;
  for (int i = 0; i < p.size(); i++) {
    assert(p[i] >= i);
    ans += p[i] - i;
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n;
  cin >> n;
  vector<long long> p(n);
  long long sum = 0;
  map<long long, long long> cnt;
  for (long long i = 0; i < (long long)n; i++) {
    cin >> p[i];
    sum += p[i];
    cnt[p[i]]++;
  }
  if (sum == 0) {
    lose();
    return 0;
  }
  long long cntG2 = 0;
  long long ind = -1;
  for (auto c : cnt) {
    if (c.second > 2) {
      lose();
      return 0;
    } else if (c.second == 2) {
      cntG2++;
      ind = c.first;
    }
  }
  if (cntG2 > 1) {
    lose();
    return 0;
  }
  if (cntG2 == 1) {
    for (int i = 0; i < n; i++) {
      if (p[i] == ind) {
        if (cnt[p[i] - 1] > 0 || p[i] == 0) {
          lose();
          return 0;
        }
        break;
      }
    }
  }
  if (cntMoves(p) % 2 == 1) {
    win();
  } else {
    lose();
  }
  return 0;
}
