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 PyPy3 (2.4.0) (judge verdict: Accepted)

import sys
S = input()

if len(S)%2!=0:
    print("No")
    sys.exit()

for i in range(len(S)):
    if i%2 == 0 and S[i] == "h":
        pass
    elif i%2 == 1 and S[i] == "i":
        pass
    else:
        print("No")
        sys.exit()
print("Yes")