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 Kotlin (1.0.0) (judge verdict: Accepted)


fun main(args:Array<String>) {
    val s = readLine()!!.toMutableList()
    if(solve(s)) {
        println("Yes")
    } else {
        println("No")
    }
}

fun solve(s:MutableList<Char>):Boolean {
    if(s.size % 2 != 0) {
        return false
    }
    while (s.size > 0) {
        if(s[0] == 'h' && s[1] == 'i') {
            s.removeAt(0)
            s.removeAt(0)
        } else {
            return false
        }
    }
    return true
}