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 C# (judge verdict: Wrong Answer)

/*
 * Created by SharpDevelop.
 * User: yog-sothoth
 * Date: 2017/04/23
 * Time: 17:25
 * 
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */

using System.Collections.Generic;
using System;

namespace Dictionary
{	
	public class DictionaryList
	{
		
		public static void Main(string[] args)
		{
			//List<string> dict=new List<string>();
			int num=int.Parse(Console.ReadLine());// the number of instructions
			//repeat readline
			string[] dict=new string[num];
			for(int i=0;i<num;i++)
			{
				string iands=Console.ReadLine();//instruction and string
				string[] instAndStr=iands.Split();
				int index=0;
				if(instAndStr[0]=="insert")
				{//Add list instAndStr[1]
					dict[index]=instAndStr[1];
					index++;
				}
				else//instAndStr[0]=="find"
				{//search list instAndStr[1]
					
					if(0<=Array.IndexOf(dict,instAndStr[1]))
					{
						Console.WriteLine("yes");
					}
					else
					{
						Console.WriteLine("no");
					}
					
				}
			}
			
			
		}
		
	}
	


}