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 Kotlin (judge verdict: Accepted)

fun main(args: Array<String>){
    val n = readLine()!!.toInt()
    val dict = Dict()
    repeat(n){
        val (query, s) = readLine()!!.split(' ')
        if(query == "insert"){dict.insert(s)}
        else if(query == "find") println(if (dict.find(s)) "yes" else "no")
    }
}

class Dict{
    private val arr = IntArray(30000000){ -1 }
    fun insert(element: String){
        arr[hash(element)] = 1
    }
    fun find(element: String): Boolean{
        return arr[hash(element)] == 1
    }
}

fun Int.pow(n: Int): Int = if(n == 0) 1 else this*this.pow(n-1)

fun hash(s: String): Int{
    var ret = 0
    for(i in 0 until s.length){
        val digit = when(s[i]){
            'A' -> 1
            'C' -> 2
            'G' -> 3
            'T' -> 4
            else -> 0
        }
        ret += 5.pow(i) * digit
    }
    return ret
}