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 Python (3.4.3) (judge verdict: Wrong Answer)

hitatistr = input()
count = 0
flag = "ok"
for i in hitatistr:
  if count % 2 == 0:
    if i != "h":
      flag = "ng"
      break
  else:
    if i != "i":
      flag = "ng"
  count = count + 1
if flag == "ok":
  print("Yes")
else:
  print("No")