#include <bits/stdc++.h>
using namespace std;
long long mod = 1000000007;
long long fact[10001],inv[10001];
long long fast(long long a,long long b){
if(b==0)return 1;
if(b==1)return a;
long long h = fast(a,b/2);
h*=h;h%=mod;
if(b%2)return (h*a)%mod;
else return h;
}
long long nPr(long long a,long long b){
return (fact[a]*inv[a-b])%mod;
}
long long nCr(long long a,long long b){
return (((fact[a]*inv[a-b])%mod)*inv[b])%mod;
}
long long dp[2001][2001];
int n,m;int cnt[2001];
long long solve(int i,int rem){
if(i==m){
return fact[rem*2];
}
if(dp[i][rem]!=-1)return dp[i][rem];
long long de = 1;
long long all =0;
for(int j = 0;j<=cnt[i]/2;j++){
all+=(((((solve(i+1,rem-j)*nPr(cnt[i],j*2))%mod)*nCr(rem,j))%mod)*de)%mod;
all%=mod;
de*=(mod-1);de%=mod;
}
return dp[i][rem] = all;
}
signed main(){
ios_base::sync_with_stdio(false);cin.tie(0);
memset(dp,-1,sizeof dp);
fact[0] = 1;inv[0] = fast(fact[0],mod-2);
for(long long i = 1;i<=1e4;i++){
fact[i]=(fact[i-1]*i)%mod;
inv[i]=fast(fact[i],mod-2);
}
cin>>n>>m;
for(int i = 0;i<2*n;i++){
cnt[i%m]++;
}
cout<<solve(0,n)<<endl;
}
