#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int kMod = 1e9 + 7;
void addSelf(int &x, int y) {
x += y;
if(x >= kMod) {
x -= kMod;
}
}
int add(int x, int y) {
addSelf(x, y);
return x;
}
void multSelf(int &x, int y) {
x = (ll)x * y % kMod;
}
int mult(int x, int y) {
multSelf(x, y);
return x;
}
const int kN = 2000;
int dp[2][2 * kN + 1], comb[2 * kN + 1][2 * kN + 1];
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int n, m;
cin >> n >> m;
vector<int> cnt(m);
for(int i = 0; i < 2 * n; i++) {
cnt[i % m]++;
}
comb[0][0] = 1;
for(int i = 1; i <= 2 * n; i++) {
comb[i][0] = comb[i][i] = 1;
for(int j = 1; j < i; j++) {
comb[i][j] = add(comb[i - 1][j], comb[i - 1][j - 1]);
}
}
int sum = cnt[0];
dp[0][sum] = 1;
for(int i = 1; i < m; i++) {
int fact = 1;
for(int j = 0; j <= cnt[i]; j++) {
for(int k = j; k <= sum; k++) {
int ways = dp[(i - 1) & 1][k];
multSelf(ways, comb[cnt[i]][j]);
multSelf(ways, comb[k][j]);
multSelf(ways, fact);
addSelf(dp[i & 1][k + cnt[i] - 2 * j], ways);
}
multSelf(fact, j + 1);
}
for(int k = 0; k <= sum; k++) {
dp[(i - 1) & 1][k] = 0;
}
sum += cnt[i];
}
int res = dp[(m - 1) & 1][0];
for(int i = 1; i <= n; i++) {
multSelf(res, 2);
multSelf(res, i);
}
cout << res << '\n';
return 0;
}
