You are a coach at your local university. There are n students under your supervision, the programming skill of the i-th student is a_i.

You have to form k teams for yet another new programming competition. As you know, the more students are involved in competition the more probable the victory of your university is! So you have to form no more than k (and at least one) non-empty teams so that the total number of students in them is maximized. But you also know that each team should be balanced. It means that the programming skill of each pair of students in each team should differ by no more than 5. Teams are independent from one another (it means that the difference between programming skills of two students from two different teams does not matter).

It is possible that some students not be included in any team at all.

Your task is to report the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.

If you are Python programmer, consider using PyPy instead of Python when you submit your code.

Input

The first line of the input contains two integers n and k (1 ≤ k ≤ n ≤ 5000) — the number of students and the maximum number of teams, correspondingly.

The second line of the input contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9), where a_i is a programming skill of the i-th student.

Output

Print one integer — the maximum possible total number of students in no more than k (and at least one) non-empty balanced teams.

Examples

Input


5 2
1 2 15 15 15


Output


5


Input


6 1
36 4 1 25 9 16


Output


2


Input


4 4
1 10 100 1000


Output


4
import javafx.util.Pair;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;
import java.util.function.BiFunction;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.UnaryOperator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import static java.lang.Math.abs;

public class problem1 {

    boolean ONLINE_JUDGE = (System.getProperty("ONLINE_JUDGE") != null);

    public problem1() throws IOException {
        InputReader in;
        if (ONLINE_JUDGE) {
            in = new InputReader(System.in);
        } else {
            in = new InputReader(new FileInputStream("input.txt"));
        }
        PrintWriter out = new PrintWriter(System.out);

        int T = 1;
        for (int caseNo = 1; caseNo <= T; caseNo++) {
            solve(caseNo, in, out);
        }

        out.close();
    }

    int lower_bound(int arr[], int key, int low, int high)
    {
        if (low > high)
            //return -1;
            return low;

        int mid = low + ((high - low) >> 1);
        //if (arr[mid] == key) return mid;

        //Attention here, we go left for lower_bound when meeting equal values
        if (arr[mid] >= key)
            return lower_bound(arr, key, low, mid - 1);
        else
            return lower_bound(arr, key, mid + 1, high);
    }


    private void solve(int caseNo, InputReader in, PrintWriter out) throws IOException {

        int n = in.nextInt(), k = in.nextInt();

        int dyn[][] = new int [k + 1][n + 1];
        int arr[] = new int[n];

        for (int i = 0; i < n; ++i) {
            arr[i] = in.nextInt();
        }
        Arrays.sort(arr);

        int ans = 0;
        for (int i = 0; i < k; ++i) {
            for (int j = 0; j < n; ++j) {
                if (j > 0) dyn[i][j] = max(dyn[i][j], dyn[i][j - 1]);

                int acc = arr[j] + 5;
                int ind = abs(lower_bound(arr, acc + 1, 0, n - 1)) ;

                dyn[i + 1][ind ] = max(dyn[i + 1][ind ], dyn[i][j] + ind - j);
                ans = max(ans, dyn[i + 1][ind ]);
            }
        }

        out.println(ans);
    }

    static class InputReader {

        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public interface SpaceCharFilter {

            public boolean isSpaceChar(int ch);
        }

        public String next() {
            return nextString();
        }

        public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public Long nextLong() {
            return Long.parseLong(nextString());
        }

        public Double nextDouble() {
            return Double.parseDouble(nextString());
        }

        public char nextCharacter() {
            return nextString().charAt(0);
        }

        public int[] nextIntArray(int N) {
            int A[] = new int[N];
            for (int i = 0; i < N; i++) {
                A[i] = nextInt();
            }
            return A;
        }

        public long[] nextLongArray(int N) {
            long A[] = new long[N];
            for (int i = 0; i < N; i++) {
                A[i] = nextLong();
            }
            return A;
        }

        public double[] nextDoubleArray(int N) {
            double A[] = new double[N];
            for (int i = 0; i < N; i++) {
                A[i] = nextDouble();
            }
            return A;
        }
    }

    int min(int... a) {
        int min = Integer.MAX_VALUE;
        for (int v : a) {
            min = Math.min(min, v);
        }
        return min;
    }

    long min(long... a) {
        long min = Long.MAX_VALUE;
        for (long v : a) {
            min = Math.min(min, v);
        }
        return min;
    }

    double min(double... a) {
        double min = Double.MAX_VALUE;
        for (double v : a) {
            min = Math.min(min, v);
        }
        return min;
    }

    int max(int... a) {
        int max = Integer.MIN_VALUE;
        for (int v : a) {
            max = Math.max(max, v);
        }
        return max;
    }

    long max(long... a) {
        long max = Long.MIN_VALUE;
        for (long v : a) {
            max = Math.max(max, v);
        }
        return max;
    }

    double max(double... a) {
        double max = Double.MIN_VALUE;
        for (double v : a) {
            max = Math.max(max, v);
        }
        return max;
    }

    private void debug(Object... o) {
        if (ONLINE_JUDGE) {
            return;
        }
        System.out.println(Arrays.deepToString(o));
    }

    public static void main(String args[]) throws IOException {
        new problem1();
    }
}