program main
  implicit none
  character(len=10) :: S
  integer :: i,N
  logical :: flag
  read(*,*) S
  N = len_trim(S)
  if ( mod(N,2) == 1) then
     write(*,'(a)') 'No'
     stop
  else
     flag = .false.
     do  i = 1,N,2
        if (S(i:i+1) == "hi") then
           flag = .true.
        else
           flag = .false.
        end if
     end do
  end if
  if ( flag )then
     write(*,'(a)') 'Yes'
  else 
     write(*,'(a)') 'No'
  end if
end program main
