program main
integer :: n,length,i,cnt = 0
character*10,allocatable :: s(:)
 
read(*,*) n
allocate(s(n))
read(*,*)(s(i),i = 1,n)
 
do i = 1,n
s= pack(s,s /= s(i))
cnt = cnt + 1
if (size(s) == 0) exit
end do
 
write(*,*)cnt
end program main