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>
 
const int N = 16777217;
 
int n;
char data[16777217];
 
int conv(char c){
  switch(c){
  case 'A':
    return 1;
    break;
  case 'C':
    return 2;
    break;
  case 'G':
    return 3;
    break;
  case 'T':
    return 4;
    break;
  }
}
 
int hash(char str[10]){
  int res = 0, size = strlen(str), r = 1, i;
  for(i=size-1;i>=0;i--){
    res += r * conv(str[i]);
    r *= 4;
  }
  return res;
}
 
void insertElm(int d){
  data[d] = 1;
}
 
char findElm(int d){
  return data[d];
}
 
main(){
  char ope[13], str[13];
  int i;
  memset(data, 0, 16777217);
  scanf("%d", &n);
  for(i=0;i<n;i++){
    scanf("%s", ope);
    scanf("%s", str);
    if(!strcmp(ope, "insert")) insertElm(hash(str));
    else printf("%s\n", (findElm(hash(str)) ? "yes" : "no"));
  }
  return 0;
}