#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define all(v) begin(v), end(v)
#define pi pair<int, int>
#define vi vector<int>
using namespace std;
const ll mod=1e9+7, maxn = 3e3+3;
ll n, m, nn, mm, dp[maxn][maxn], dp2[maxn][maxn];
bool c[maxn][maxn], c2[maxn][maxn];
ll solve2(ll n,ll m){
if(m==0) return 1;
if(c2[n][m]) return dp2[n][m];
c2[n][m]=true;
dp2[n][m] = solve2(n,m-1);
if(n>=1)dp2[n][m] += solve2(n-1,m-1)*n*4;
if(n>=2)dp2[n][m] += solve2(n-2,m-1)*n*(n-1)/2;
return dp2[n][m] = dp2[n][m]%mod;
}
ll solve(ll n,ll m){
if(n==0) return solve2(nn-(mm-m)/2,m);
if(c[n][m]) return dp[n][m];
c[n][m]=true;
dp[n][m] = solve(n-1,m);
if(m>=2) dp[n][m] += solve(n-1,m-2)*m*(m-1)/2;
return dp[n][m] = dp[n][m]%mod;
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> m;
nn=n, mm=m;
cout << solve(n,m)-1;
return 0;
}
