Even Chef have Friends!

Published on August 28, 2021
Last updated August 28, 2021

Chef decided to find the connections with all of his friends in an unnamed social network. He calls a user of the social network his friend if there is a common substring of the string “chef” and the nickname of that user with length ≥ 2.

Given a list of users of the social network, compute the number of Chef’s friends.

Input Format

The first line of the input contains a single integer N denoting the number of users in the social network.

N lines follow. Each of these lines contains a single string u denoting the nickname of one user.


1 ≤ N ≤ 5,000
3 ≤ |u| ≤ 20

each character of each user’s nickname is either a lowercase English letter (‘a’-‘z’) or ’.’

the first character of each user’s nickname is a lowercase English letter.

Output Format

Print a single line containing one integer — the number of Chef’s friends.

Sample Input


Sample Output



gennady.korotkevich is a friend to Chef because he has “ch” at the end of his nickname, which is also a substring of “chef” with length 2

The common substring with kefaa is “ef” and the common substring with chemthan is “che”

Solution in java

import java.util.Scanner;

class chefAndFriends {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int num_of_cases = sc.nextInt();
        int count = 0;
        while (num_of_cases-- > 0) {
            String s = sc.next();
            String chef = "chef";
            for (int i = 0; i < s.length() - 1; i++) {
                String sub = s.substring(i, i + 2);
                if (chef.contains(sub)) {

Tags :