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: Accepted)

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
typedef long long ll;
typedef long double ld;
#define rep(i,l,r)for(ll i=(l);i<(r);i++)
#define repp(i,l,r,k)for(ll i=(l);i<(r);i+=(k))
#define INF (1LL<<60)
#define MOD1 1000000007

void swap(ll *a, ll *b){ll c;c=*b;*b=*a;*a=c;}/*swap 交換*/
ll max2(ll a,ll b){return a>=b?a:b;}/*2つのうち大きい数を返す*/ 
ll min2(ll a,ll b){return a>=b?b:a;}/*2つのうち小さい数を返す*/ 
ll ABS(ll a){return a>=0?a:(-a);}/*絶対値*/ 
int upll(const void*a, const void*b){return*(ll*)a<*(ll*)b?-1:*(ll*)a>*(ll*)b?1:0;}
int downll(const void*a, const void*b){return*(ll*)a<*(ll*)b?1:*(ll*)a>*(ll*)b?-1:0;}
void sortup(ll*a,int n){qsort(a,n,sizeof(ll),upll);}
void sortdown(ll*a,int n){qsort(a,n,sizeof(ll),downll);}

typedef struct{
    ll aa;
    ll bb;
}frequent;

int main(void){
    char s[15];
    ll n;
    scanf("%s",s);
    n=strlen(s);
    if(n%2==1){
        printf("No\n");
        return 0;
    }
    rep(i,0,n-1){
        if(s[i]=='h'&& s[i+1]=='i' ){
            i++;
        }else{
            printf("No\n");
            return 0;
        }
    }
    printf("Yes\n");
    return 0;
}