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 java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.io.BufferedWriter;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author prakharjain
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        EKBalancedTeams solver = new EKBalancedTeams();
        solver.solve(1, in, out);
        out.close();
    }

    static class EKBalancedTeams {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n = in.nextInt();

            int k = in.nextInt();

            if (k >= n) {
                out.println(n);
                return;
            }

            Integer[] a = in.nextIntArrayBoxed(n);

            Arrays.sort(a);

            int[] ans = new int[n];

            ans[0] = 0;

            for (int i = 1; i < n; i++) {
                int lo = 0;
                int hi = i - 1;

                int li = i;
                while (lo <= hi) {
                    int mid = (lo + hi) / 2;

                    if (a[mid] + 5 >= a[i]) {
                        li = mid;
                        hi = mid - 1;
                    } else {
                        lo = mid + 1;
                    }
                }

                ans[i] = li;
            }

            int[][] dp = new int[n + 1][n + 1];

            for (int i = 1; i <= n; i++) {
                for (int j = 0; j <= n; j++) {
                    //use
//                if (j < n)
//                    dp[ans[i - 1] + 1][j + 1] = Math.max(dp[ans[i - 1] + 1][j + 1], dp[i - 1][j] + (ans[i - 1] - i + 1));
                    if (j > 0) {
                        int li = ans[i - 1];
                        dp[i][j] = dp[li][j - 1] + (i - li);
                    }
                    //not
                    dp[i][j] = Math.max(dp[i][j], dp[i - 1][j]);
                }
            }

            out.println(dp[n][k]);
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.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 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 boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public Integer[] nextIntArrayBoxed(int n) {
            Integer[] array = new Integer[n];
            for (int i = 0; i < n; ++i) array[i] = nextInt();
            return array;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
}

