#include <iostream>
#include <algorithm>
using namespace std;
#define int long long
int const N=4e3+10,mod=1e9+7;
int fac[N],inv[N];
int dp[N][N]={};// fixing j numbers within first 1.....i mod m
int power(int x,int y)
{
int res=1;
while (y)
{
if (y&1)
res=(res*x)%mod;
x=(x*x)%mod;
y>>=1;
}
return res;
}
int add(int a,int b)
{
return ((a+b)%mod+mod)%mod;
}
int mul(int a,int b)
{
return (a*b)%mod;
}
int nCr(int n,int r)
{
if (r>n)
return 0;
return mul(fac[n],mul(inv[r],inv[n-r]));
}
int nPr(int n,int r)
{
if (r>n)
return 0;
return mul(fac[n],inv[n-r]);
}
inline void solve()
{
int n,m;
cin>>n>>m;
int cnt[m+1]={};
for (int i=1;i<=2*n;i++)
cnt[i%m+1]++;
dp[0][0]=1;
for (int i=1;i<=m;i++)
{
dp[i][0]=1;
for (int j=1;j<=n;j++)
{
for (int k=0;k<=j&&2*k<=cnt[i];k++)
{
dp[i][j]=add(dp[i][j],mul(dp[i-1][j-k],mul(nPr(cnt[i],2*k),nCr(j,k))));
}
}
}
int ans=0;
int cof=-1;
for (int i=1;i<=n;i++)
{
ans=add(ans,cof*mul(fac[2*(n-i)],mul(nCr(n,i),dp[m][i])));
cof=-cof;
}
ans=add(ans,fac[2*n]);
cout<<ans<<endl;
}
signed main()
{
ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
fac[0]=inv[0]=1;
for (int i=1;i<N;i++)
{
fac[i]=mul(fac[i-1],i);
inv[i]=power(fac[i],mod-2);
}
int t=1;
for (int i=1;i<=t;i++)
solve();
}
