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<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<string>
#include<cmath>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<vector>
#include<complex>
#include<unordered_map>
#define deg(x) cout<<#x<<"="<<x<<endl;
#define fd(x) for(int i=0;i<x;i++)
#define fdd(a,x) for(int i=a;i<x;i++)
#define fx(x,n) for(int i=n-1;i>=x;i--)
#define mst(x) memset(x,0,sizeof(x));
#define fi first
#define se second
#define TB ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
#define ok "ok"
#define HH puts("");
#define ls rt<<1
#define rs rt<<1|1
#define pb(a,b) a.push_back(b);
#define FIN  freopen("1.in","r",stdin);
#define FOUT freopen("1.out","w",stdout);
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<string,int> pss;
typedef unsigned long long ull;
const ll mod=1e18;
const ll inf=1e18;
const double eps=1e-8;
const double pi=acos(-1);


int main(){
    //TB
    string s;
    cin>>s;
    int f=0,k=1,flag=1;
    while(f<s.length()){
        if(s.length()==k) {
            flag=0;break;
        }
        if(s[f]!='h'||s[k]!='i'){
            flag=0;break;
        }
        f+=2;k+=2;
    }
    if(flag) cout<<"Yes\n";
    else cout<<"No\n";
    return 0;
}