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 Fortran (gfortran v4.8.4) (judge verdict: Wrong Answer)

program main
    implicit none
    integer i,flag
    integer length
    character s*10

    flag = 0

    read(*,*) s
    
    length = len_trim(s)

    do i = 1,length
        if (mod(i,2) == 1) then
            if (s(i:i) == "h") then
                flag = 0
            else 
                flag = 1
            end if
        else if (mod(i,2) == 0) then
            if (s(i:i) == "i") then
                flag = 0
            else 
                flag = 1
            end if
        end if

        if (flag == 1) then
            write(*,*) "No"
            exit
        end if

    end do

    if (length >= 2) then
        if(flag == 0) then
            write(*,*) "Yes"
        end if
    else 
        write(*,*) "No"
    end if


end program