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)

from copy import deepcopy
string_in = input()
count_num = 0
for i in range(10):
  count_num += string_in.count('%d'%(i))
if count_num==0:
  check_str = "hi"        
  max_count = string_in.count(check_str)
  check_obj = ["hi"*i for i in range(1,max_count+1)][::-1]
  string_in4 = deepcopy(string_in)
  count = 0
  for i in range(len(check_obj)):
    i_str = str(check_obj[i])
    string_in4 = string_in4.replace(i_str, '%d'%(i))
    count += string_in4.count('%d'%(i))
  if count==0:
    print("No")
  else:
    print("Yes")
else:
  print("Yes")