implicit none
  integer::i, N, maxeto
  integer::a(12)=0
  character(len=7)::str(50)

  read *, N
  read *, str(1:N)
  do i=1, N
     select case(str(i))
     case('ne     ')
        a( 1) = a( 1) + 1
     case('ushi   ')
        a( 2) = a( 2) + 1
     case('tora   ')
        a( 3) = a( 3) + 1
     case('u      ')
        a( 4) = a( 4) + 1
     case('tatsu  ')
        a( 5) = a( 5) + 1
     case('mi     ')
        a( 6) = a( 6) + 1
     case('uma    ')
        a( 7) = a( 7) + 1
     case('hitsuji')
        a( 8) = a( 8) + 1
     case('saru   ')
        a( 9) = a( 9) + 1
     case('tori   ')
        a(10) = a(10) + 1
     case('inu    ')
        a(11) = a(11) + 1
     case('i      ')
        a(12) = a(12) + 1
     end select
  end do
  maxeto = MAXVAL(a)
  if(2*maxeto-1 .le.N ) then
     print '(a)',"YES"
  else
     print '(a)',"NO"
  end if

end program