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 Ruby (2.3.3) (judge verdict: Wrong Answer)

str = gets
len = str.length
ans = 0
key = 0

if	len%2 == 1
	ans = 1
else
  
len.times do |i|
	if key == 0
		if str[i] == "h"
			key = 1
		else
			ans = 1
          	break
		end
	else
		if str[i] == "i"
			key = 0
		else
			ans = 1
          	break
		end
	end
end
end

if ans == 0
	puts "Yes"
else
	puts "No"
end