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 Scala (2.11.7) (judge verdict: Accepted)

object Main extends App {                                                                                                                                      import scala.util.matching.Regex
  val sc = new java.util.Scanner (System.in)
  val s:String = sc.nextLine
  val pattern:Regex = "(hi)+".r
  val result = s match {
    case pattern(_) => println("Yes")
    case _ => println("No")
  }
}