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: Accepted)

#include<iostream>
#include<cstdio>
#include<string>
#include<map>
using namespace std;

int main() {
  int n;
  char str[10], com[13];
  map<string, bool>  T;

  cin >> n;
  for ( int i = 0; i < n; i++ ) {
    scanf("%s%s", com, str);
    if ( com[0] == 'i' ) T[string(str)] = true;
    else {
      if ( T[string(str)] ) printf("yes\n");
      else printf("no\n");
    }
  }

  return 0;
}