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 Rust (judge verdict: Accepted)

use std::collections::HashMap;
fn main() {
    let mut buf = String::new();
    let _ = std::io::stdin().read_line(&mut buf).ok();
    let n:usize = buf.trim().parse().unwrap();
    let mut map = HashMap::new();
    for _ in 0..n {
        let mut buf = String::new();
        let _ = std::io::stdin().read_line(&mut buf).ok();
        let mut buf = buf.split_whitespace();
        let inst: &str = buf.next().unwrap();
        let op  = buf.next().unwrap().to_string();
        if inst == "insert" {
            map.insert(op, 0);
        } else if inst == "find" {
            if map.contains_key(&op) {
                println!("yes");
            } else {
                println!("no");
            }
        }
    }
}