let checkNum num lst = 
	if List.mem num lst then lst
	else num :: lst 

let get_data () = 
	let index = int_of_string(read_line())
	in 
	let rec sub i result =
		if i < index then  	
			let num = int_of_string(read_line())  
			in sub (i + 1) (checkNum num result)
		else result
	in sub 0 []		
		

let solve () = 
	print_int (List.length (get_data()));;

solve()