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 JavaScript (judge verdict: Wrong Answer)

var input = require('fs').readFileSync('/dev/stdin', 'utf8');
var lines = input.split('\n');

lines.shift();

var dic = {};
lines.forEach(function (line) {
	var command = line.split(' ');
	if (command[0] == 'insert')
		dic[command[1]] = true;
	else {
		if (dic[command[1]]) {
			console.log('yes');
		} else {
			console.log('no');
		}
	}
});