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 Ruby (judge verdict: Time Limit Exceeded)

def add word
	h1, h2 = getHashV word
	h = h1
	i = 0
	while @dic[h]
		i += 1
		h = (h1 + h2 * i) % @dic.length
	end
	@dic[h] = word
end

def find word
	h1, h2 = getHashV word
	h = h1
	i = 0
	while true
		return true if @dic[h] == word
		return false unless @dic[h]
		i += 1
		h = (h1 + h2 * i) % @dic.length
	end
end

def getHashV word
	num = toN word
	[hashF1(num), hashF2(num)]
end

def hashF1 num
	num % @dic.length
end

def hashF2 num
	num % (@dic.length - 1) + 1
end

def toN word
	num = word.dup
	num.gsub!("A", "1")
	num.gsub!("C", "2")
	num.gsub!("G", "3")
	num.gsub!("T", "4")
	num.to_i
end

n = gets.to_i
@dic = Array.new(1999993)
n.times{
	command, word = gets.chomp.split
	case command
	when "insert"
		add word
	else
		puts (find word) ? "yes" : "no"
	end
}