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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
int main()
{
  char s[11];
  scanf("%s",&s);
  int i;
  i = 1;
  while (s[i])
  {
    if (s[i] != 'i' && s[i] != 'h')
      break;
    else if (s[i - 1] == 'h' && s[i] != 'i')
      break;
    else if (s[i] == 'i' && (s[i + 1] != 'h' && s[i + 1] != '\0'))
      break;
    if (s[i] == 'i' && s[i - 1] == 'h' && i % 2 != 0)
    {
      printf("Yes");
      return (0);
    }
    i++;
  }
  printf("No");
}