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)

S = input()
count = 0
count_h = 0
count_i = 0
for i in range(len(S)-1):
  if S[i] == 'h' and S[i+1] == 'i':
    count = 1
for i in range(len(S)):
  if S[i] == 'h':
    count_h = count_h+1
  elif S[i] == 'i':
    count_i = count_i+1
    
if count == 1 and len(S)%2 == 0 and count_h == count_i:
  print('Yes')
else:
  print('No')