Problem:
Search III

Your task is to write a program of a simple dictionary which implements the following instructions:

insert str: insert a string str in to the dictionary

find str: if the distionary contains str, then print 'yes', otherwise print 'no'

Input

In the first line n, the number of instructions is given. In the following n lines, n instructions are given in the above mentioned format.

Output

Print yes or no for each find instruction in a line.

Constraints

A string consists of 'A', 'C', 'G', or 'T'

1 ≤ length of a string ≤ 12

n ≤ 1000000

Sample Input 1

5
insert A
insert T
insert C
find G
find A

Sample Output 1

no
yes

Sample Input 2

13
insert AAA
insert AAC
insert AGA
insert AGG
insert TTT
find AAA
find CCC
find CCC
insert CCC
find CCC
insert T
find TTT
find T

Sample Output 2

yes
no
no
yes
yes
yes

Notes

Template in C

Solution in JAVA (judge verdict: Wrong Answer)

import java.io.*;
import java.util.*;

public class Main {
    
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        ArrayList<String> array = new ArrayList<String>();
        
        int N = in.nextInt();
        for (int i = 0; i < N; i++){
            String c1 = in.next();
            String c2 = in.next();
            
            if (c1.equals("insert")){
                array.add(c2);
            }else if(c1.equals("find")){   
                if (array.contains(c2)){
                    System.out.println("yes");
                }else{
                    System.out.println("no");
                }
            }
            
            System.out.println(c2);
        }
    }
}