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'

Notes

Template in C

Constraints

* A string consists of 'A', 'C', 'G', or 'T'
* 1 ≤ length of a string ≤ 12
* n ≤ 1000000

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.

Examples

Input

5
insert A
insert T
insert C
find G
find A


Output

no
yes


Input

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


Output

yes
no
no
yes
yes
yes
import java.util.Scanner;

public class Main{
    public static void main(String arg[]){
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        int count;
        int[] str=new int[10000000];//A,C,G,T
        for(int i=0;i<n;i++){
            count=0;
            String a=sc.next();
            String b=sc.next();
            for(int j=0;j<b.length();j++){
                if(b.charAt(j)=='A')count+=1*Math.pow(5,j);
                else if(b.charAt(j)=='C')count+=2*Math.pow(5,j);
                else if(b.charAt(j)=='G')count+=3*Math.pow(5,j);
                else count+=4*Math.pow(5,j);
            }
            if(a.equals("insert")){
                str[count]++;
            }else{
                if(str[count]==0)System.out.println("no");
                else System.out.println("yes");
            }
        }
        sc.close();
    }
}
