#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
using ll = long long;
ll lgpow(int b, int e)
{
if(!e)
return 1;
ll x = lgpow(b, e >> 1);
if(e & 1)
return x * (x * b % mod) % mod;
return x * x % mod;
}
const int N = 2000;
ll dp[N + 5][2 * N + 5];
ll fact[2 * N + 5], inv[2 * N + 5];
void precalc()
{
fact[0] = 1;
for(int i = 1; i <= 2 * N; i ++)
fact[i] = fact[i - 1] * i % mod;
inv[2 * N] = lgpow(fact[2 * N], mod - 2);
for(int i = 2 * N; i; i --)
inv[i - 1] = inv[i] * i % mod;
}
int comb(int k, int n)
{
if(k < 0 || k > n || n < 0)
return 0;
return fact[n] * inv[k] % mod * inv[n - k] % mod;
}
signed main()
{
precalc();
int n, m;
cin >> n >> m;
dp[0][0] = 1;
for(int i = 1; i <= m; i ++)
{
int nr = 0;
if(i == 1)
nr = (2 * n) / m;
else
for(int j = i - 1; j <= 2 * n; j += m)
nr ++;
for(int j = 0; j <= 2 * n; j ++)
for(int k = 0; k <= min(j, nr); k ++)
dp[i][nr + j - 2 * k] += dp[i - 1][j] * (fact[j] * inv[j - k] % mod) % mod * comb(k, nr),
dp[i][nr + j - 2 * k] %= mod;
}
cout << lgpow(2, n) * dp[m][0] % mod * fact[n] % mod;
}
