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<stdio.h>
#include<string.h>
char ha[1<<21],k[256];
int main(int argc,char *argv[]){
  int i,flg;
  int val,s,t;
  char c;
  k['T'] = 1;
  k['G'] = 2;
  k['C'] = 3;
  k['A'] = 4;
  
  scanf("%d", &val);
  getchar();
  for(i=0;i<val;i++){
    s = 0;
    t = 1;
    flg = ( c = getchar() ) == 'i';
    while ( ( c = getchar() ) != ' ' );
    while ( ( c = k[getchar()] ) != 0 ) {
      s += c * t;
      t *= 4;
    }
    if (flg) ha[s] = 1; else puts( ha[s] ? "yes" : "no" );
  }
  return 0;
}