6580: Dictionary
[Creator : ]
Description
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.
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 $≤ 124
$n ≤ 1,000,000$
$1 ≤$ length of a string $≤ 124
$n ≤ 1,000,000$
Sample 1 Input
5
insert A
insert T
insert C
find G
find A
Sample 1 Output
no
yes
Sample 2 Input
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 2 Output
yes
no
no
yes
yes
yes