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

int main() {
  string s;
  cin>>s;
  int n=s.size();
  bool ans=true;
  if (n%2==1) ans=false;
  else {
    rep(i,n/2) {
      if (s[i*2]!='h'||s[i*2+1]!='i') ans=false;
    }
  }
  cout<<(ans ? "Yes":"No")<<endl;
  return 0;
}