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: Runtime Error)

s=input()
for i in range(len(s)-1):
    if(s[i]=='h'):
        if(s[i+1]=='i'):
            continue
        else:
            print('No')
            exit()
    elif(s[i]=='i'):
        if(s[i+1]=='h'):
            if(s[i+2]=='i'):
                continue
            else:
                print('No')
                exit()
        else:
            print('No')
            exit()
    else:
        print('No')
        exit()
print('Yes')