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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iomanip>
#include <iostream>
#define rep(i, n) for (int i = 0; i < (n); i++)
using namespace std;

int main(void) {
  ios::sync_with_stdio(false);
  string S;
  cin >> S;
  int n = S.size();
  if (n % 2) {
    cout << "No" << endl;
    return 0;
  }

  for (int i = 0; i < n; i += 2) {
    if (S[i] == 'h' && S[i + 1] == 'i') {
      ;
    } else {
      cout << "No" << endl;
      return 0;
    }
  }
  cout << "Yes" << endl;
  return 0;
}