#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx,avx2")
using namespace std;
typedef long long ll;
typedef __int128 lll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pld;
#define MAX 9223372036854775807LL
#define MIN -9223372036854775807LL
#define INF 0x3f3f3f3f3f3f3f3f
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cout << fixed; cout.precision(10);
#define sp << " "
#define en << "\n"
#define compress(v) sort(v.begin(), v.end()), v.erase(unique(v.begin(), v.end()), v.end())
ll n, m;
ll ss = 1000000007;
ll ans;
ll cou[2010];
ll dp[9000010];
ll fac[5010] = {0, }, inv[5010] = {0, };
ll num(ll X, ll Y)
{
return X * (m + 1) + Y;
}
ll power(ll xx, ll yy)
{
ll ret = 1;
while(yy > 0)
{
if(yy % 2)
ret = (ret * xx) % ss;
xx = (xx * xx) % ss;
yy /= 2;
}
return ret;
}
ll C(ll xx, ll yy)
{
if(xx < yy)
return 0;
if(xx == yy || !yy)
return 1;
long long r = (fac[xx] * inv[xx - yy]) % ss;
r = (r * inv[yy]) % ss;
return r;
}
void init(void)
{
fac[0] = 1;
fac[1] = 1;
for(ll i = 2 ; i <= 4500 ; i++)
fac[i] = (fac[i - 1] * i) % ss;
inv[4500] = power(fac[4500], ss - 2);
for(ll i = 4499 ; i >= 0 ; i--)
inv[i] = (inv[i + 1] * (i + 1)) % ss;
}
int main(void)
{
fastio
cin >> n >> m;
init();
ll siz = n * 2;
ans = fac[siz];
for(ll i = 1 ; i <= siz ; ++i)
{
ll gap = i % m;
if(gap == 0)
gap = m;
cou[gap]++;
}
for(ll i = 0 ; i <= m ; ++i)
dp[num(0, i)] = 1;
for(ll i = 1 ; i <= n ; ++i)
{
for(ll j = 1 ; j <= m ; ++j)
{
ll X = cou[j];
for(ll k = 1 ; k * 2 <= X && k <= i ; ++k)
dp[num(i, j)] = (dp[num(i, j)] + dp[num(i - k, j - 1)] * C(X, k * 2) % ss * fac[k * 2] % ss * C(i, k) % ss) % ss;
}
for(ll j = 1 ; j <= m ; ++j)
dp[num(i, j)] = (dp[num(i, j)] + dp[num(i, j - 1)]) % ss;
}
for(ll i = 1 ; i <= n ; ++i)
{
ll gap = dp[num(i, m)] * C(n, i) % ss * fac[n * 2 - i * 2] % ss;
if(i & 1)
ans = (ans - gap);
else
ans = (ans + gap);
while(abs(ans) > ss)
{
if(ans < 0)
ans += ss;
else
ans -= ss;
}
}
ans = (ans + ss) % ss;
cout << ans;
return 0;
}
