import java.util.ArrayList;
import java.util.Scanner;

public class Main {
	static int waruketa = 1;
	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		ArrayList<Integer> list = new ArrayList<>();
		int N = scn.nextInt();
		for (int i = 0; i < N; i++) {
			list.add(scn.nextInt());
		}

		for (int i = 0; i < list.size(); i++) {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		}
		System.out.println(list.size());
	}
} import java.util.ArrayList; ArrayList java.util import java.util.Scanner; Scanner java.util public class Main {
	static int waruketa = 1;
	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		ArrayList<Integer> list = new ArrayList<>();
		int N = scn.nextInt();
		for (int i = 0; i < N; i++) {
			list.add(scn.nextInt());
		}

		for (int i = 0; i < list.size(); i++) {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		}
		System.out.println(list.size());
	}
} Main static int waruketa = 1; waruketa 1 public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		ArrayList<Integer> list = new ArrayList<>();
		int N = scn.nextInt();
		for (int i = 0; i < N; i++) {
			list.add(scn.nextInt());
		}

		for (int i = 0; i < list.size(); i++) {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		}
		System.out.println(list.size());
	} main {
		Scanner scn = new Scanner(System.in);
		ArrayList<Integer> list = new ArrayList<>();
		int N = scn.nextInt();
		for (int i = 0; i < N; i++) {
			list.add(scn.nextInt());
		}

		for (int i = 0; i < list.size(); i++) {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		}
		System.out.println(list.size());
	} Scanner scn = new Scanner(System.in); scn new Scanner(System.in) ArrayList<Integer> list = new ArrayList<>(); list new ArrayList<>() int N = scn.nextInt(); N scn.nextInt() scn.nextInt scn for (int i = 0; i < N; i++) {
			list.add(scn.nextInt());
		} int i = 0; int i = 0; i 0 i < N i N i++ i++ i {
			list.add(scn.nextInt());
		} {
			list.add(scn.nextInt());
		} list.add(scn.nextInt()) list.add list scn.nextInt() scn.nextInt scn for (int i = 0; i < list.size(); i++) {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		} int i = 0; int i = 0; i 0 i < list.size() i list.size() list.size list i++ i++ i {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		} {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		} int x = list.get(i); x list.get(i) list.get list i for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			} int j = 0; int j = 0; j 0 j < i-1 j i-1 i 1 {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			} {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			} if (x == list.get(j)) {
					list.remove(j);
					continue;
				} x == list.get(j) x list.get(j) list.get list j {
					list.remove(j);
					continue;
				} list.remove(j) list.remove list j continue; j++ j for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			} int j = i+1; int j = i+1; j i+1 i 1 j < list.size() j list.size() list.size list {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			} {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			} if (x == list.get(j)) {
					list.remove(j);
					continue;
				} x == list.get(j) x list.get(j) list.get list j {
					list.remove(j);
					continue;
				} list.remove(j) list.remove list j continue; j++ j System.out.println(list.size()) System.out.println System.out System System.out list.size() list.size list String[] args args public class Main {
	static int waruketa = 1;
	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		ArrayList<Integer> list = new ArrayList<>();
		int N = scn.nextInt();
		for (int i = 0; i < N; i++) {
			list.add(scn.nextInt());
		}

		for (int i = 0; i < list.size(); i++) {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		}
		System.out.println(list.size());
	}
} public class Main {
	static int waruketa = 1;
	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		ArrayList<Integer> list = new ArrayList<>();
		int N = scn.nextInt();
		for (int i = 0; i < N; i++) {
			list.add(scn.nextInt());
		}

		for (int i = 0; i < list.size(); i++) {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		}
		System.out.println(list.size());
	}
} Main
import java.util.ArrayList;
import java.util.Scanner;

public class Main {
	static int waruketa = 1;
	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		ArrayList<Integer> list = new ArrayList<>();
		int N = scn.nextInt();
		for (int i = 0; i < N; i++) {
			list.add(scn.nextInt());
		}

		for (int i = 0; i < list.size(); i++) {
			int x = list.get(i);
			for (int j = 0; j < i-1;) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				j++;
			}
			for (int j = i+1; j < list.size();) {
				if (x == list.get(j)) {
					list.remove(j);
					continue;
				}
				 j++;
			}
		}
		System.out.println(list.size());
	}
}
