import java.io.*;
import java.io.IOException;
import java.util.*;

class Main {
    final static int INF = 1 << 28;
    final static long LNF = 1L << 60;
    final static double EPS = 1e-9;
    final static double GOLDEN_RATIO = (1.0 + Math.sqrt(5)) / 2.0;

    static final long MOD = 1_000_000_007;

    public static void main(String[] args) throws Exception {
        final MyScanner sc = new MyScanner();
        long N;
        N = sc.nextLong();
        long[] d = new long[(int)(N)];
        for(int i = 0 ; i < N ; i++){
                d[i] = sc.nextLong();
        }
        solve(N, d);
    }

    static void solve(long N, long[] d){
        HashSet<Long> hoge = new HashSet<>();
        for (Long long1 : d) {
            hoge.add(long1);
        }
        System.out.println(hoge.size());
        
    }


    static class MyScanner {
 
        BufferedReader br;
        StringTokenizer st;
 
        MyScanner(FileReader fileReader) {
            br = new BufferedReader(fileReader);
        }
 
        MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
 
        String nn() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        String next() {
            String ans = "";
            try {
                ans = br.readLine();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            return ans;
        }
 
        char nextChar() {
            return nn().charAt(0);
        }
 
        int nextInt() {
            return Integer.parseInt(nn());
        }
 
        long nextLong() {
            return Long.parseLong(nn());
        }
 
        double nextDouble() {
            return Double.parseDouble(nn());
        }
 
        Integer[] niArr0(int n) {
            Integer[] ar = new Integer[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        }
 
        Integer[] niArr1(int n) {
            Integer[] ar = new Integer[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        }
 
        Long[] nlArr0(int n) {
            Long[] ar = new Long[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        }
 
        Long[] nlArr1(int n) {
            Long[] ar = new Long[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        }
    }

} import java.io.*; io.* java import java.io.IOException; IOException java.io import java.util.*; util.* java class Main {
    final static int INF = 1 << 28;
    final static long LNF = 1L << 60;
    final static double EPS = 1e-9;
    final static double GOLDEN_RATIO = (1.0 + Math.sqrt(5)) / 2.0;

    static final long MOD = 1_000_000_007;

    public static void main(String[] args) throws Exception {
        final MyScanner sc = new MyScanner();
        long N;
        N = sc.nextLong();
        long[] d = new long[(int)(N)];
        for(int i = 0 ; i < N ; i++){
                d[i] = sc.nextLong();
        }
        solve(N, d);
    }

    static void solve(long N, long[] d){
        HashSet<Long> hoge = new HashSet<>();
        for (Long long1 : d) {
            hoge.add(long1);
        }
        System.out.println(hoge.size());
        
    }


    static class MyScanner {
 
        BufferedReader br;
        StringTokenizer st;
 
        MyScanner(FileReader fileReader) {
            br = new BufferedReader(fileReader);
        }
 
        MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
 
        String nn() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        String next() {
            String ans = "";
            try {
                ans = br.readLine();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            return ans;
        }
 
        char nextChar() {
            return nn().charAt(0);
        }
 
        int nextInt() {
            return Integer.parseInt(nn());
        }
 
        long nextLong() {
            return Long.parseLong(nn());
        }
 
        double nextDouble() {
            return Double.parseDouble(nn());
        }
 
        Integer[] niArr0(int n) {
            Integer[] ar = new Integer[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        }
 
        Integer[] niArr1(int n) {
            Integer[] ar = new Integer[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        }
 
        Long[] nlArr0(int n) {
            Long[] ar = new Long[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        }
 
        Long[] nlArr1(int n) {
            Long[] ar = new Long[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        }
    }

} Main final static int INF = 1 << 28; INF 1 << 28 1 28 final static long LNF = 1L << 60; LNF 1L << 60 1L 60 final static double EPS = 1e-9; EPS 1e-9 final static double GOLDEN_RATIO = (1.0 + Math.sqrt(5)) / 2.0; GOLDEN_RATIO (1.0 + Math.sqrt(5)) / 2.0 (1.0 + Math.sqrt(5)) 1.0 Math.sqrt(5) Math.sqrt Math 5 2.0 static final long MOD = 1_000_000_007; MOD 1_000_000_007 public static void main(String[] args) throws Exception {
        final MyScanner sc = new MyScanner();
        long N;
        N = sc.nextLong();
        long[] d = new long[(int)(N)];
        for(int i = 0 ; i < N ; i++){
                d[i] = sc.nextLong();
        }
        solve(N, d);
    } main {
        final MyScanner sc = new MyScanner();
        long N;
        N = sc.nextLong();
        long[] d = new long[(int)(N)];
        for(int i = 0 ; i < N ; i++){
                d[i] = sc.nextLong();
        }
        solve(N, d);
    } final MyScanner sc = new MyScanner(); sc new MyScanner() long N; N N = sc.nextLong() N sc.nextLong() sc.nextLong sc long[] d = new long[(int)(N)]; d new long[(int)(N)] (int)(N) for(int i = 0 ; i < N ; i++){
                d[i] = sc.nextLong();
        } int i = 0 ; int i = 0 ; i 0 i < N i N i++ i++ i {
                d[i] = sc.nextLong();
        } {
                d[i] = sc.nextLong();
        } d[i] = sc.nextLong() d[i] d i sc.nextLong() sc.nextLong sc solve(N, d) solve N d String[] args args static void solve(long N, long[] d){
        HashSet<Long> hoge = new HashSet<>();
        for (Long long1 : d) {
            hoge.add(long1);
        }
        System.out.println(hoge.size());
        
    } solve {
        HashSet<Long> hoge = new HashSet<>();
        for (Long long1 : d) {
            hoge.add(long1);
        }
        System.out.println(hoge.size());
        
    } HashSet<Long> hoge = new HashSet<>(); hoge new HashSet<>() for (Long long1 : d) {
            hoge.add(long1);
        } Long long1 d {
            hoge.add(long1);
        } {
            hoge.add(long1);
        } hoge.add(long1) hoge.add hoge long1 System.out.println(hoge.size()) System.out.println System.out System System.out hoge.size() hoge.size hoge long N N long[] d d static class MyScanner {
 
        BufferedReader br;
        StringTokenizer st;
 
        MyScanner(FileReader fileReader) {
            br = new BufferedReader(fileReader);
        }
 
        MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
 
        String nn() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        String next() {
            String ans = "";
            try {
                ans = br.readLine();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            return ans;
        }
 
        char nextChar() {
            return nn().charAt(0);
        }
 
        int nextInt() {
            return Integer.parseInt(nn());
        }
 
        long nextLong() {
            return Long.parseLong(nn());
        }
 
        double nextDouble() {
            return Double.parseDouble(nn());
        }
 
        Integer[] niArr0(int n) {
            Integer[] ar = new Integer[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        }
 
        Integer[] niArr1(int n) {
            Integer[] ar = new Integer[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        }
 
        Long[] nlArr0(int n) {
            Long[] ar = new Long[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        }
 
        Long[] nlArr1(int n) {
            Long[] ar = new Long[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        }
    } MyScanner BufferedReader br; br StringTokenizer st; st MyScanner(FileReader fileReader) {
            br = new BufferedReader(fileReader);
        } MyScanner {
            br = new BufferedReader(fileReader);
        } br = new BufferedReader(fileReader) br new BufferedReader(fileReader) FileReader fileReader fileReader MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        } MyScanner {
            br = new BufferedReader(new InputStreamReader(System.in));
        } br = new BufferedReader(new InputStreamReader(System.in)) br new BufferedReader(new InputStreamReader(System.in)) String nn() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        } nn {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        } while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } st == null || !st.hasMoreElements() st == null st null !st.hasMoreElements() st.hasMoreElements() st.hasMoreElements st {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } IOException e {
                    e.printStackTrace();
                } e.printStackTrace() e.printStackTrace e {
                    st = new StringTokenizer(br.readLine());
                } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st String next() {
            String ans = "";
            try {
                ans = br.readLine();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            return ans;
        } next {
            String ans = "";
            try {
                ans = br.readLine();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            return ans;
        } String ans = ""; ans "" try {
                ans = br.readLine();
            } catch (IOException ex) {
                ex.printStackTrace();
            } catch (IOException ex) {
                ex.printStackTrace();
            } IOException ex {
                ex.printStackTrace();
            } ex.printStackTrace() ex.printStackTrace ex {
                ans = br.readLine();
            } ans = br.readLine() ans br.readLine() br.readLine br return ans; ans char nextChar() {
            return nn().charAt(0);
        } nextChar {
            return nn().charAt(0);
        } return nn().charAt(0); nn().charAt(0) nn().charAt nn() nn 0 int nextInt() {
            return Integer.parseInt(nn());
        } nextInt {
            return Integer.parseInt(nn());
        } return Integer.parseInt(nn()); Integer.parseInt(nn()) Integer.parseInt Integer nn() nn long nextLong() {
            return Long.parseLong(nn());
        } nextLong {
            return Long.parseLong(nn());
        } return Long.parseLong(nn()); Long.parseLong(nn()) Long.parseLong Long nn() nn double nextDouble() {
            return Double.parseDouble(nn());
        } nextDouble {
            return Double.parseDouble(nn());
        } return Double.parseDouble(nn()); Double.parseDouble(nn()) Double.parseDouble Double nn() nn Integer[] niArr0(int n) {
            Integer[] ar = new Integer[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        } niArr0 {
            Integer[] ar = new Integer[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        } Integer[] ar = new Integer[n]; ar new Integer[n] n for (int i = 0; i < n; i++) {
                ar[i] = nextInt();
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                ar[i] = nextInt();
            } {
                ar[i] = nextInt();
            } ar[i] = nextInt() ar[i] ar i nextInt() nextInt return ar; ar int n n Integer[] niArr1(int n) {
            Integer[] ar = new Integer[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        } niArr1 {
            Integer[] ar = new Integer[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        } Integer[] ar = new Integer[n + 1]; ar new Integer[n + 1] n + 1 n 1 for (int i = 1; i <= n; i++) {
                ar[i] = nextInt();
            } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
                ar[i] = nextInt();
            } {
                ar[i] = nextInt();
            } ar[i] = nextInt() ar[i] ar i nextInt() nextInt return ar; ar int n n Long[] nlArr0(int n) {
            Long[] ar = new Long[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        } nlArr0 {
            Long[] ar = new Long[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        } Long[] ar = new Long[n]; ar new Long[n] n for (int i = 0; i < n; i++) {
                ar[i] = nextLong();
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                ar[i] = nextLong();
            } {
                ar[i] = nextLong();
            } ar[i] = nextLong() ar[i] ar i nextLong() nextLong return ar; ar int n n Long[] nlArr1(int n) {
            Long[] ar = new Long[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        } nlArr1 {
            Long[] ar = new Long[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        } Long[] ar = new Long[n + 1]; ar new Long[n + 1] n + 1 n 1 for (int i = 1; i <= n; i++) {
                ar[i] = nextLong();
            } int i = 1; int i = 1; i 1 i <= n i n i++ i++ i {
                ar[i] = nextLong();
            } {
                ar[i] = nextLong();
            } ar[i] = nextLong() ar[i] ar i nextLong() nextLong return ar; ar int n n
import java.io.*;
import java.io.IOException;
import java.util.*;

class Main {
    final static int INF = 1 << 28;
    final static long LNF = 1L << 60;
    final static double EPS = 1e-9;
    final static double GOLDEN_RATIO = (1.0 + Math.sqrt(5)) / 2.0;

    static final long MOD = 1_000_000_007;

    public static void main(String[] args) throws Exception {
        final MyScanner sc = new MyScanner();
        long N;
        N = sc.nextLong();
        long[] d = new long[(int)(N)];
        for(int i = 0 ; i < N ; i++){
                d[i] = sc.nextLong();
        }
        solve(N, d);
    }

    static void solve(long N, long[] d){
        HashSet<Long> hoge = new HashSet<>();
        for (Long long1 : d) {
            hoge.add(long1);
        }
        System.out.println(hoge.size());
        
    }


    static class MyScanner {
 
        BufferedReader br;
        StringTokenizer st;
 
        MyScanner(FileReader fileReader) {
            br = new BufferedReader(fileReader);
        }
 
        MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
 
        String nn() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        String next() {
            String ans = "";
            try {
                ans = br.readLine();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            return ans;
        }
 
        char nextChar() {
            return nn().charAt(0);
        }
 
        int nextInt() {
            return Integer.parseInt(nn());
        }
 
        long nextLong() {
            return Long.parseLong(nn());
        }
 
        double nextDouble() {
            return Double.parseDouble(nn());
        }
 
        Integer[] niArr0(int n) {
            Integer[] ar = new Integer[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        }
 
        Integer[] niArr1(int n) {
            Integer[] ar = new Integer[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextInt();
            }
            return ar;
        }
 
        Long[] nlArr0(int n) {
            Long[] ar = new Long[n];
            for (int i = 0; i < n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        }
 
        Long[] nlArr1(int n) {
            Long[] ar = new Long[n + 1];
            for (int i = 1; i <= n; i++) {
                ar[i] = nextLong();
            }
            return ar;
        }
    }

}
