#include <bits/stdc++.h>
using namespace std;
int a[110000];
int n;
char lost[] = "cslnb";
char win[] = "sjfnb";
long long tot = 0;
long long ans = 0;
int ptr = 0;
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i];
  sort(a + 1, a + n + 1);
  for (int i = 2; i <= n; i++) {
    if (a[i - 1] == 0 && a[i] == 0) cout << lost, exit(0);
    if (a[i - 1] == a[i]) ptr++;
    if (a[i - 1] == a[i] && i > 2 && a[i - 2] + 1 >= a[i])
      cout << lost, exit(0);
  }
  if (ptr > 1) cout << lost << endl, exit(0);
  for (int i = 1; i <= n; i++) tot += a[i], tot -= (i - 1);
  if (tot % 2 == 0)
    cout << lost << endl;
  else
    cout << win << endl;
}
