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 Go (1.6) (judge verdict: Accepted)

package main

import (
  "fmt"
  "regexp"
)

func main() {
  var s string
  fmt.Scan(&s)
  r := regexp.MustCompile(`^(hi)+$`)
  if r.MatchString(s) {
    fmt.Println("Yes")
  } else {
    fmt.Println("No")
  }
}