Problem: There are n students in a class working on group projects. The students will divide into groups (some students may be in groups alone), work on their independent pieces, and then discuss the results together. It takes the i-th student ai minutes to finish his/her independent piece.

If students work at different paces, it can be frustrating for the faster students and stressful for the slower ones. In particular, the imbalance of a group is defined as the maximum ai in the group minus the minimum ai in the group. Note that a group containing a single student has an imbalance of 0. How many ways are there for the students to divide into groups so that the total imbalance of all groups is at most k?

Two divisions are considered distinct if there exists a pair of students who work in the same group in one division but different groups in the other.

Input

The first line contains two space-separated integers n and k (1 ≤ n ≤ 200, 0 ≤ k ≤ 1000) — the number of students and the maximum total imbalance allowed, respectively.

The second line contains n space-separated integers ai (1 ≤ ai ≤ 500) — the time it takes the i-th student to complete his/her independent piece of work.

Output

Print a single integer, the number of ways the students can form groups. As the answer may be large, print its value modulo 109 + 7.

Examples

Input

3 2
2 4 5


Output

3


Input

4 3
7 8 9 10


Output

13


Input

4 0
5 10 20 21


Output

1

Note

In the first sample, we have three options: 

  * The first and second students form a group, and the third student forms a group. Total imbalance is 2 + 0 = 2. 
  * The first student forms a group, and the second and third students form a group. Total imbalance is 0 + 1 = 1. 
  * All three students form their own groups. Total imbalance is 0. 



In the third sample, the total imbalance must be 0, so each student must work individually.

Solution (in JAVA):

Solution:
import java.io.*;
import static java.lang.Math.*;

import java.lang.reflect.Array;
import java.util.*;
import java.lang.*;

public class Main {
    final static boolean debug = false;
    final static String fileName = "";
    final static boolean useFiles = false;

    public static void main(String[] args) throws FileNotFoundException {
        PrintWriter writer = new PrintWriter(System.out);
        new Task(new InputReader(System.in), writer).solve();
        writer.close();
    }
}

class InputReader {
    public BufferedReader reader;
    public StringTokenizer tokenizer;

    public InputReader(InputStream stream) {
        reader = new BufferedReader(new InputStreamReader(stream), 32768);
        tokenizer = null;
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public byte nextByte() {
        return Byte.parseByte(next());
    }
}

class Task {
    final int mod = (int)(1e9 + 7);

    public void solve() {
        int n = in.nextInt();
        int k = in.nextInt();
        int[] a = new int[n];
        for (int i = 0; i < n; i++){
            a[i] = in.nextInt();
        }
        Arrays.sort(a);
        int[][][] d = new int[2][n + 1][k + 1];
        d[0][0][0] = 1;
        d[0][1][0] = 1;
        int cur = 0;
        for (int i = 0; i < n - 1; i++, cur = 1 - cur){
            for (int open = 0; open < n; open++)
                for (int kk = 0; kk <= k; kk++) d[1 - cur][open][kk] = 0;

            for (int open = 0; open < n; open++){
                for (int kk = 0; kk <= k; kk++) {
                    int b = d[cur][open][kk];

                    int to = kk + open * (a[i + 1] - a[i]);
                    if (to <= k) {
                        d[1 - cur][open][to] = (int)((d[1 - cur][open][to] + (open + 1) * (long)b) % mod);
                        if (0 <= open - 1)
                            d[1 - cur][open - 1][to] = (int)((d[1 - cur][open - 1][to] + open * (long)b) % mod);

                        if (open + 1 < n)
                            d[1 - cur][open + 1][to] = (d[1 - cur][open + 1][to] + b) % mod;
                    }
                }
            }
        }
//        for (int i = 0; i < n; i++){
//            for (int open = 0; open < n; open++){
//                for (int kk = 0; kk <= k; kk++){
//                    out.println(i + " " + open + " " + kk + " " + d[i][open][kk]);
//                }
//            }
//        }
        int result = 0;
        for (int i = 0; i <= k; i++){
            result = (result + d[cur][0][i]) % mod;
        }
        out.println(result);
    }

    private InputReader in;
    private PrintWriter out;

    Task(InputReader in, PrintWriter out) {
        this.in = in;
        this.out = out;
    }
}