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
            exit
        end if

    end do

    if (mod(length,2) == 1) then
        flag = 1
    end if
    
    if(flag == 0) then
        write(*,*) "Yes"
    else 
        write(*,*) "No"
    end if

end program