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 Ruby (2.3.3) (judge verdict: Accepted)

# ENV[Z = 'RUBY_THREAD_VM_STACK_SIZE'] || exec( { Z => '50000000' },'ruby',$0)
# readlines.map(&:chomp!).map { |e| e.split.map(&:to_i) }
# gets.split.map(&:to_i)
s = gets.chomp!
matched = /(hi)+/.match(s)
if matched && matched[0] == s
  puts 'Yes'
else
  puts 'No'
end