import java.io.IOException;
import java.util.Arrays;

public class Main {

	public static void main(String[] args) throws Exception {
		int N = nextInt();
		int[] input = new int[N];
		for (int i = 0; i < N; i++) {
			input[i] = nextInt();
		}
		Arrays.sort(input);
		int ans = 0;
		for (int i = 0; i < N; i++) {
			if ((i == 0 || input[i - 1] != input[i]) && (i == N - 1 || input[i] != input[i + 1])) {
				ans++;
			}
		}
		System.out.println(ans);
	}

	static int nextInt() {
		int c;
		try {
			c = System.in.read();
			while (c != '-' && (c < '0' || c > '9'))
				c = System.in.read();
			if (c == '-')
				return -nextInt();
			int res = 0;
			while (c >= '0' && c <= '9') {
				res = res * 10 + c - '0';
				c = System.in.read();
			}
			return res;
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return -1;
	}
}