program hitachi_string
  implicit none
  character(10) :: s
  integer :: n = 0, i
  read(*,*) s
  n = len_trim(s)
  if (mod(n,2) == 0) then
    do i = 1, n, 2
      if (s(i:i+1) /= "hi") goto 100
    end do
    write(*,'(a)') "Yes"
    stop
  end if
100 write(*,'(a)') "No"
end program hitachi_string