#include <bits/stdc++.h>
using namespace std;
int a[100005], bi;
char s[2][10] = {"sjfnb", "cslnb"};
int main() {
  int n, st = 0, pre = 0, cur = -1, ct = 0;
  bool io = false;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", a + i);
  sort(a, a + n);
  for (int i = 0; i < n; i++) {
    if (a[i] == cur) {
      ct++;
      if (ct == 2 && cur == 0 || ct > 2 || (ct == 2 && pre == cur - 1) || io) {
        printf("%s", s[1]);
        return 0;
      }
      io = true;
    } else {
      pre = cur;
      cur = a[i];
      ct = 1;
    }
  }
  for (int i = 0; i < n; i++) {
    if (a[i] >= st) {
      bi = (bi + (a[i] - st) % 2) % 2;
      st++;
    }
  }
  printf("%s", s[1 - bi]);
}
