from fractions import gcd
# from datetime import date, timedelta
# from heapq import *
import heapq
import math
from collections import defaultdict, Counter, deque
from bisect import *
import itertools
import fractions
import sys
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
# input = sys.stdin.readline


def lcm(a, b):
    return a * b / fractions.gcd(a, b)


def make_divisors(n):
    divisors = []
    for i in range(1, int(n**0.5)+1):
        if n % i == 0:
            divisors.append(i)
            if i != n // i:
                divisors.append(n//i)

    # divisors.sort()
    return divisors


def factorize(n):
    fct = []  # prime factor
    b, e = 2, 0  # base, exponent
    while b * b <= n:
        while n % b == 0:
            n = n // b
            e = e + 1
        if e > 0:
            fct.append((b, e))
        b, e = b + 1, 0
    if n > 1:
        fct.append((n, 1))
    return fct


def is_prime(n):
    if n == 1:
        return False

    for k in range(2, int(math.sqrt(n)) + 1):
        if n % k == 0:
            return False

    return True


def primes(n):
    is_prime = [True] * (n + 1)
    is_prime[0] = False
    is_prime[1] = False
    for i in range(2, int(n**0.5) + 1):
        if not is_prime[i]:
            continue
        for j in range(i * 2, n + 1, i):
            is_prime[j] = False
    return [i for i in range(n + 1) if is_prime[i]]

def modpow(a, n, mod):
    res = 1
    while n > 0:
        if n & 1:
            res = res * a % mod
        a = a * a % mod
        n >>= 1
    return res


def modinv(a, mod):
    return modpow(a, mod - 2, mod)


def cnk(a, b):
    MOD = 10**9+7
    ret = 1
    for i in range(b):
        ret *= (a-i)
        ret %= MOD
        ret = ret * modinv(i+1, MOD) % MOD
    return ret


class UnionFind:
    def __init__(self, n):
        self.sz = [-1 for i in range(n)]

    # 検索
    def find(self, x):
        if self.sz[x] < 0:
            return x
        else:
            self.sz[x] = self.find(self.sz[x])
            return self.sz[x]

    # 併合
    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return False
        if self.sz[x] > self.sz[y]:
            x, y = y, x
        self.sz[x] += self.sz[y]
        self.sz[y] = x

    # 同じ集合に属するか判定
    def same(self, x, y):
        return self.find(x) == self.find(y)

    # xが含まれている集合のサイズを求める
    def size(self, x):
        return -self.sz[self.find(x)]


def main():
    s = input()
    f = False
    for i in range(0 , len(s),2):
        if s[i] == "h" and s[i + 1] == "i":
            pass
        else:
            print("No")
            exit()


    print("Yes")
  


if __name__ == '__main__':
    main()


### FIXED CODE ###

from fractions import gcd
# from datetime import date, timedelta
# from heapq import *
import heapq
import math
from collections import defaultdict, Counter, deque
from bisect import *
import itertools
import fractions
import sys
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
# input = sys.stdin.readline


# def lcm(a, b):
#     return a * b / fractions.gcd(a, b)


# def make_divisors(n):
#     divisors = []
#     for i in range(1, int(n**0.5)+1):
#         if n % i == 0:
#             divisors.append(i)
#             if i != n // i:
#                 divisors.append(n//i)

#     # divisors.sort()
#     return divisors


# def factorize(n):
#     fct = []  # prime factor
#     b, e = 2, 0  # base, exponent
#     while b * b <= n:
#         while n % b == 0:
#             n = n // b
#             e = e + 1
#         if e > 0:
#             fct.append((b, e))
#         b, e = b + 1, 0
#     if n > 1:
#         fct.append((n, 1))
#     return fct


# def is_prime(n):
#     if n == 1:
#         return False

#     for k in range(2, int(math.sqrt(n)) + 1):
#         if n % k == 0:
#             return False

#     return True


# def primes(n):
#     is_prime = [True] * (n + 1)
#     is_prime[0] = False
#     is_prime[1] = False
#     for i in range(2, int(n**0.5) + 1):
#         if not is_prime[i]:
#             continue
#         for j in range(i * 2, n + 1, i):
#             is_prime[j] = False
#     return [i for i in range(n + 1) if is_prime[i]]

# def modpow(a, n, mod):
#     res = 1
#     while n > 0:
#         if n & 1:
#             res = res * a % mod
#         a = a * a % mod
#         n >>= 1
#     return res


# def modinv(a, mod):
#     return modpow(a, mod - 2, mod)


# def cnk(a, b):
#     MOD = 10**9+7
#     ret = 1
#     for i in range(b):
#         ret *= (a-i)
#         ret %= MOD
#         ret = ret * modinv(i+1, MOD) % MOD
#     return ret


# class UnionFind:
#     def __init__(self, n):
#         self.sz = [-1 for i in range(n)]

#     # 検索
#     def find(self, x):
#         if self.sz[x] < 0:
#             return x
#         else:
#             self.sz[x] = self.find(self.sz[x])
#             return self.sz[x]

#     # 併合
#     def union(self, x, y):
#         x = self.find(x)
#         y = self.find(y)
#         if x == y:
#             return False
#         if self.sz[x] > self.sz[y]:
#             x, y = y, x
#         self.sz[x] += self.sz[y]
#         self.sz[y] = x

#     # 同じ集合に属するか判定
#     def same(self, x, y):
#         return self.find(x) == self.find(y)

#     # xが含まれている集合のサイズを求める
#     def size(self, x):
#         return -self.sz[self.find(x)]


def main():
    s = input()
    if (len(s)) % 2 == 1:
        print("No")
        exit()
    for i in range(0 , len(s),2):
        if s[i] == "h" and s[i + 1] == "i":
            pass
        else:
            print("No")
            exit()


    print("Yes")
  


if __name__ == '__main__':
    main()