using System;
using System.Linq;
using System.Collections.Generic;
using System.Diagnostics;
using Debug = System.Diagnostics.Trace;
using SB = System.Text.StringBuilder;
using System.Numerics;
using static System.Math;
using Number = System.Int64;
namespace Program {
	public class Solver {
		Random rnd = new Random();
		public void Solve() {
			var n = ri * 2; var k = ri;
			var a = Enumerate(k, x => new int[] { ri - 1, ri - 1 });

			var dp = Enumerate(n, x => new ModInt[n]);
			var ep = Enumerate(n, x => new ModInt[n]);
			for (int i = 0; i < n; i++)
				for (int j = 0; j < n; j++)
					dp[i][j] = ep[i][j] = -1;
			ModInt[] f = new ModInt[n + 5];
			f[0] = 1;
			for (int i = 2; i <= n; i += 2)
				f[i] = f[i - 2] * (i - 1);
			Func<int, int, ModInt> efs = null;
			efs = (l, r) => {
				if (ep[l][r].num != -1) return ep[l][r];
				var cnt = 0;
				foreach (var v in a) {
					if (l <= v[0] && v[0] <= r) cnt++;
					if (l <= v[1] && v[1] <= r) cnt++;
					if (cnt % 2 == 1) return dp[l][r] = 0;
				}
				return ep[l][r] = f[r - l + 1 - cnt];
			};
			Func<int, int, ModInt> dfs = null;
			dfs = (l, r) => {
				if (dp[l][r].num != -1) return dp[l][r];
				var ret = efs(l, r);
				for (int i = l + 1; i < r; i += 2)
					ret = ret - dfs(l, i) * efs(i + 1, r);
				return dp[l][r] = ret;
			};
			ModInt ans = 0;
			for (int l = 0; l < n; l++)
				for (int r = l + 1; r < n; r++) {
					var add = dfs(l, r);
					if (add.num == 0) continue;
					var cnt = 0;
					foreach (var v in a) {
						if (l <= v[0] && v[0] <= r) cnt++;
						if (l <= v[1] && v[1] <= r) cnt++;
					}
					var rem = n - (r - l + 1);
					rem -= 2 * k - cnt;
					add *= f[rem];
					Debug.WriteLine($"{l + 1} {r + 1} {add}");
					ans += add;
				}
			Console.WriteLine(ans);
		}

		const long INF = 1L << 60;
		static int[] dx = { -1, 0, 1, 0 };
		static int[] dy = { 0, 1, 0, -1 };
		int ri { get { return sc.Integer(); } }
		long rl { get { return sc.Long(); } }
		double rd { get { return sc.Double(); } }
		string rs { get { return sc.Scan(); } }
		public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());

		static T[] Enumerate<T>(int n, Func<int, T> f) {
			var a = new T[n];
			for (int i = 0; i < n; ++i) a[i] = f(i);
			return a;
		}
		static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
	}
}

#region main
static class Ex {
	static public string AsString(this IEnumerable<char> ie) { return new string(ie.ToArray()); }
	static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") {
		return string.Join(st, ie);
	}
	static public void Main() {
		//Console.SetOut(new Program.IO.Printer(Console.OpenStandardOutput()) { AutoFlush = false });
		var solver = new Program.Solver();
		solver.Solve();
		Console.Out.Flush();
	}
}
#endregion
#region Ex
namespace Program.IO {
	using System.IO;
	using System.Text;
	using System.Globalization;

	public class Printer : StreamWriter {
		public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
		public Printer(Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
	}

	public class StreamScanner {
		public StreamScanner(Stream stream) { str = stream; }

		public readonly Stream str;
		private readonly byte[] buf = new byte[1024];
		private int len, ptr;
		public bool isEof = false;
		public bool IsEndOfStream { get { return isEof; } }

		private byte read() {
			if (isEof) return 0;
			if (ptr >= len) {
				ptr = 0;
				if ((len = str.Read(buf, 0, 1024)) <= 0) {
					isEof = true;
					return 0;
				}
			}
			return buf[ptr++];
		}

		public char Char() {
			byte b = 0;
			do b = read(); while ((b < 33 || 126 < b) && !isEof);
			return (char)b;
		}
		public string Scan() {
			var sb = new StringBuilder();
			for (var b = Char(); b >= 33 && b <= 126; b = (char)read()) sb.Append(b);
			return sb.ToString();
		}
		public string ScanLine() {
			var sb = new StringBuilder();
			for (var b = Char(); b != '\n' && b != 0; b = (char)read()) if (b != '\r') sb.Append(b);
			return sb.ToString();
		}
		public long Long() { return isEof ? long.MinValue : long.Parse(Scan()); }
		public int Integer() { return isEof ? int.MinValue : int.Parse(Scan()); }
		public double Double() { return isEof ? double.NaN : double.Parse(Scan(), CultureInfo.InvariantCulture); }
	}
}

#endregion
#region ModInt
/// <summary>
/// [0,<see cref="Mod"/>) までの値を取るような数
/// </summary>
public struct ModInt {
	public const long Mod = (int)1e9 + 7;
	public long num;
	public ModInt(long n) { num = n; }
	public override string ToString() => num.ToString();
	public static ModInt operator +(ModInt l, ModInt r) => new ModInt(l.num + r.num < Mod ? l.num + r.num : l.num + r.num - Mod);
	public static ModInt operator -(ModInt l, ModInt r) => new ModInt(l.num + Mod - r.num < Mod ? l.num + Mod - r.num : l.num - r.num);
	public static ModInt operator *(ModInt l, ModInt r) => new ModInt(l.num * r.num % Mod);
	public static ModInt operator /(ModInt l, ModInt r) => l * Inverse(r);
	public static implicit operator ModInt(long n) => new ModInt(n);
	public static ModInt Pow(ModInt v, long k) { return Pow(v.num, k); }
	public static ModInt Pow(long v, long k) {
		long ret = 1;
		for (k %= Mod - 1; k > 0; k >>= 1, v = v * v % Mod)
			if ((k & 1) == 1) ret = ret * v % Mod;
		return new ModInt(ret);
	}
	public static ModInt Inverse(ModInt v) { return Pow(v, Mod - 2); }
	public static ModInt Modulo(long v) => new ModInt(((v % Mod) + Mod) % Mod);
}
#endregion


Measured memory_bytes: 20556