import java.io.BufferedReader
import java.io.InputStreamReader
import java.util.*

fun main(args: Array<String>) {
    val br = BufferedReader(InputStreamReader(System.`in`))
    val n = br.readLine().toInt()
    println(Array(n, {i -> br.readLine().toInt() }).toSet().size)
}

fun err(print: Any) {
    System.err.println(print)
}