Problem:
Score : 100 points

Problem Statement

A Hitachi string is a concatenation of one or more copies of the string hi.

For example, hi and hihi are Hitachi strings, while ha and hii are not.

Given a string S, determine whether S is a Hitachi string.

Constraints

The length of S is between 1 and 10 (inclusive).

S is a string consisting of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If S is a Hitachi string, print Yes; otherwise, print No.

Sample Input 1

hihi

Sample Output 1

Yes

hihi is the concatenation of two copies of hi, so it is a Hitachi string.

Sample Input 2

hi

Sample Output 2

Yes

Sample Input 3

ha

Sample Output 3

No

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::io::*;

fn main() {
    let stdin = stdin();
    let mut handle = stdin.lock();
    let mut input: String = read(&mut handle);

    let mut hitachi_iter = "hi".chars().cycle();

    for input_iter in input.chars() {
        if input_iter != hitachi_iter.next().unwrap() {
            println!("No");
            return;
        }
    }
    if input.pop().unwrap() != 'i' {
        println!("No");
    } else {
        println!("Yes");
    }
}

fn read(handle: &mut StdinLock) -> String {
    handle
        .bytes()
        .map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>()
}