#include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr char FIRST_WIN[] = "sjfnb\n";
constexpr char SECOND_WIN[] = "cslnb\n";
bool firstWins(map<ll, int> &occs) {
  ll sum = 0;
  ll ct = 0;
  for (auto pp : occs) {
    if (pp.second == 1) {
      ++ct;
      sum += pp.first;
    }
  }
  return ((sum - ((ct - 1) * ct / 2)) % 2 == 1);
}
int main() {
  int n;
  scanf("%d", &n);
  vector<ll> arr(n);
  for (int i = 0; i < n; ++i) scanf("%lld", &arr[i]);
  map<ll, int> elemct;
  for (ll x : arr) elemct[x]++;
  int totalnd = 0;
  for (auto pp : elemct)
    if (pp.second > 1) totalnd += pp.second;
  if (totalnd > 2) {
    printf(SECOND_WIN);
    return 0;
  }
  int toLower = -1;
  for (auto pp : elemct)
    if (pp.second == 2) toLower = pp.first;
  if (toLower == 0 || elemct.count(toLower - 1) > 0) {
    printf(SECOND_WIN);
    return 0;
  }
  bool firstWin = false;
  if (toLower == -1) {
    firstWin = firstWins(elemct);
  } else {
    elemct[toLower]--;
    elemct[toLower - 1]++;
    firstWin = !firstWins(elemct);
  }
  if (firstWin)
    printf(FIRST_WIN);
  else
    printf(SECOND_WIN);
  return 0;
}
