#include <bits/stdc++.h>
#define rep(a, b, c) for (int a = (b); (a) <= (c); a++)
#define per(a, b, c) for (int a = (b); (a) >= (c); a--)
#define nl '\n'
#define ioi exit(0);
const int mod = (int)1e9 + 7;
const int N = (int)1e4;
using namespace std;
void add(int &x, int y) {
x += y;
if (x >= mod) x -= mod;
if (x < 0) x += mod;
}
int sum(int x, int y) {
add(x, y);
return x;
}
int bp(int x, int y) {
int res = 1;
while (y) {
if (y & 1) res = res * 1ll * x % mod;
x = x * 1ll * x % mod, y >>= 1;
}
return res;
}
int n, m;
int f[N], rv[N];
int dp[3001][3001];
int cnk(int x, int y) {
return (f[x] * 1ll * rv[x - y] % mod) * 1ll * rv[y] % mod;
}
int ank(int x, int y) {
return f[x] * 1ll * rv[x - y] % mod;
}
int calc(int v = n, int free = m) {
if (!v) return 1;
if (~dp[v][free]) return dp[v][free];
int res = calc(v - 1, free);
// put < or > or ^ or v
if (free > 0) add(res, calc(v - 1, free - 1) * 1ll * free * 4 % mod);
// connect v and ^
// if (must > 0) add(res, calc(v + 1, free, must - 1) * 1ll * must % mod);
// open v
// if (free > 0) add(res, calc(v + 1, free - 1, must + 1) * 1ll * free % mod);
// connect > and <
if (free > 1) add(res, calc(v - 1, free - 2) * 1ll * cnk(free, 2) % mod);
return dp[v][free] = res;
}
int put[N][N];
int main() {
#ifdef IOI
freopen ("in.txt", "r", stdin);
freopen ("slow.out", "w", stdout);
#endif
f[0] = rv[0] = 1;
rep(i, 1, N - 1) {
f[i] = f[i - 1] * 1ll * i % mod;
rv[i] = bp(f[i], mod - 2);
}
cin >> n >> m;
//cout << calc()
memset(dp, -1, sizeof(dp));
int ans = sum(calc(), -1);
{
put[0][0] = 1;
rep(i, 1, m) {
rep(j, 0, i) {
put[i][j] = put[i - 1][j];
if (j > 0) add(put[i][j], put[i - 1][j - 1] * 1ll * cnk(n - 2 * (j - 1), 2) % mod);
}
}
//cerr << put[3][2] << nl;
}
rep(i, 1, n / 2) {
int take = put[m][i];
// ans = 0;
if (i <= m) add(ans, take * 1ll * calc(n - 2 * i, m - i) % mod);
//cerr << ans << ' ' << take << ' ' << calc(n - 2 * i, m - i) << nl;
}
cout << ans << nl;
ioi
}
/*
5116 0
3720 1
450 2
*/
