Problem:
Score : 200 points

Problem Statement

An X-layered kagami mochi (X ≥ 1) is a pile of X round mochi (rice cake) stacked vertically where each mochi (except the bottom one) has a smaller diameter than that of the mochi directly below it. For example, if you stack three mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, you have a 3-layered kagami mochi; if you put just one mochi, you have a 1-layered kagami mochi.

Lunlun the dachshund has N round mochi, and the diameter of the i-th mochi is d_i centimeters. When we make a kagami mochi using some or all of them, at most how many layers can our kagami mochi have?

Constraints

1 ≤ N ≤ 100

1 ≤ d_i ≤ 100

All input values are integers.

Input

Input is given from Standard Input in the following format:

N
d_1
:
d_N

Output

Print the maximum number of layers in a kagami mochi that can be made.

Sample Input 1

4
10
8
8
6

Sample Output 1

3

If we stack the mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, we have a 3-layered kagami mochi, which is the maximum number of layers.

Sample Input 2

3
15
15
15

Sample Output 2

1

When all the mochi have the same diameter, we can only have a 1-layered kagami mochi.

Sample Input 3

7
50
30
50
100
50
80
30

Sample Output 3

4

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)


import java.util.Arrays;
import java.util.Scanner;
import java.util.stream.IntStream;

public class Main {

	public static void main(String[] args) {
		//		new Main().solveA();
		new Main().solveB();
		//		new Main().solveC();
		//		new Main().solveC2();
		//		new Main().solveC3();
		// new Main().solveD();
	}

	private void solveA() {
		Scanner scanner = null;
		String line = "";

		try {
			scanner = new Scanner(System.in);
			line = scanner.next();

			System.out.println(line.replaceAll("2017", "2018"));

		} finally {
			if (scanner != null) {
				scanner.close();
			}
		}
	}

	private void solveB() {

		final Scanner scanner = new Scanner(System.in);
		int n = scanner.nextInt();
		int[] wk = IntStream.range(0, n).map(i -> scanner.nextInt()).toArray();
		//			int[] wk = new int[n];
		//
		//			for (int i = 0; i < n; i++) {
		//				wk[i] = scanner.nextInt();
		//			}

		Arrays.sort(wk);

		int res = IntStream.range(0, n).reduce(0, (sum, i) -> {
			if (i == 0) {
				sum++;
			} else if (wk[i] != wk[i - 1]) {
				sum++;
			}
			return sum;
		});
		//			int res = 0;
		//			for (int i = 0; i < wk.length; i++) {
		//				if (i == 0) {
		//					res++;
		//				} else if (wk[i] != wk[i - 1]) {
		//					res++;
		//				}
		//
		//			}

		System.out.println(res);
		if (scanner != null) {
			scanner.close();
		}
	}

	private void solveC2() {
		Scanner scanner = null;
		int n = 0;
		int y = 0;

		try {
			scanner = new Scanner(System.in);
			n = scanner.nextInt();
			y = scanner.nextInt();

			for (int i = n; i >= 0; i--) {
				if (i * 10000 > y) {
					continue;
				}
				for (int j = 0; j <= n - i; j++) {
					int k = n - i - j;
					if (i * 10000 + j * 5000 + k * 1000 == y) {
						System.out.println(i + " " + j + " " + k);
						return;
					}
				}
			}

			System.out.println(-1 + " " + -1 + " " + -1);

		} finally {
			if (scanner != null) {
				scanner.close();
			}
		}
	}

	private void solveC3() {
		Scanner scanner = null;
		int n = 0;
		int y = 0;

		try {
			scanner = new Scanner(System.in);
			n = scanner.nextInt();
			y = scanner.nextInt();

			for (int i = n; i >= 0; i--) {
				if (i * 10000 > y) {
					continue;
				}
				for (int j = 0; j <= n; j++) {
					if (i + j <= n && i * 10000 + j * 5000 + (n - i - j) * 1000 == y) {
						System.out.println(i + " " + j + " " + (n - i - j));
						return;
					}
				}
			}

			System.out.println(-1 + " " + -1 + " " + -1);

		} finally {
			if (scanner != null) {
				scanner.close();
			}
		}
	}

	private void solveC() {
		Scanner scanner = null;
		int n = 0;
		int y = 0;

		try {
			scanner = new Scanner(System.in);
			n = scanner.nextInt();
			y = scanner.nextInt();

			for (int i = n; i >= 0; i--) {
				if (i * 10000 > y) {
					continue;
				}
				for (int j = 0; j <= n - i; j++) {
					for (int k = 0; k <= n - i - j; k++) {
						if (n == i + j + k && i * 10000 + j * 5000 + k * 1000 == y) {
							System.out.println(i + " " + j + " " + k);
							return;
						}
					}
				}
			}

			System.out.println(-1 + " " + -1 + " " + -1);

		} finally {
			if (scanner != null) {
				scanner.close();
			}
		}
	}

	private void solveD() {
		Scanner scanner = null;
		int lineAB = 0;
		int lineBC = 0;
		int lineCA = 0;

		try {
			scanner = new Scanner(System.in);
			lineAB = scanner.nextInt();

			System.out.println("");

		} finally {
			if (scanner != null) {
				scanner.close();
			}
		}
	}
}