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>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define MOD 1000000007
typedef long long ll;

#define rep(i, n) for(i=0;i<(int)(n);i++)
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))
#define bit(n) (1LL<<(n))
int gcd(int a,int b){return b?gcd(b,a%b):a;}
int lcm(int a,int b){return (a*b)/gcd(a,b);}
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};

int main(void){
  char s[200001];
  int i=0,result=0,n;
  scanf("%s", s);
  n = strlen(s);
  
  for(i=0;i<n-1;i++){
    if(s[i] == 'h' && s[i+1] == 'i'){
      result = 1;
      break;
    }
  }
  
  if(result==1) printf("Yes");
  else printf("No");
  
  return 0;
}