#include <bits/stdc++.h>
using namespace std;
#define int long long
int modulo = 1e9 + 7;
int n, m;
int a[2005];
int dp[2005][2005];
int f[2005];
int fact[4005], invfact[4005];
int C(int x, int y)
{
return fact[x] * invfact[y] % modulo * invfact[x - y] % modulo;
}
int lgpow(int x, int y)
{
int z = 1;
while (y != 0)
{
if (y % 2 == 1)
z = z * x % modulo;
x = x * x % modulo;
y /= 2;
}
return z;
}
signed main()
{
fact[0] = 1;
for (int i = 1; i <= 4001; i++)
fact[i] = i * fact[i - 1] % modulo;
for (int i = 0; i <= 4001; i++)
invfact[i] = lgpow(fact[i], modulo - 2);
cin >> n >> m;
for (int i = 1; i <= 2 * n; i++)
a[(i - 1) % m + 1]++;
dp[0][0] = 1;
for (int i = 1; i <= m; i++)
{
for (int j = 0; j <= n; j++)
{
for (int q = 0; q <= j and 2 * q <= a[i]; q++)
{
int coef = dp[i - 1][j - q];
for (int r = j - q + 1; r <= j; r++)
coef = coef * (n - r + 1) % modulo;
coef = coef * C(a[i], 2 * q) % modulo;
coef = coef * fact[2 * q] % modulo;
coef = coef * invfact[q] % modulo;
dp[i][j] = (dp[i][j] + coef) % modulo;
}
//cout << i << ' ' << j << ' ' << dp[i][j] << endl;
}
}
for (int i = 0; i <= n; i++)
f[i] = dp[m][i] * fact[2 * n - 2 * i] % modulo;
int ans = 0;
for (int i = 0; i <= n; i++)
{
if (i % 2 == 0)
ans += f[i];
else
ans -= f[i];
}
ans = (ans % modulo + modulo) % modulo;
cout << ans;
return 0;
}
