#include<bits/stdc++.h>
typedef long long ll;
#define pb push_back
#define fr first
#define sc second
#define endl '\n'
using namespace std;
#define mid ((left+right)>>1)
const int mod=1e9+7;
int sum(int x,int y){
if(x+y<mod)return x+y;
return x+y-mod;
}
int sub(int x,int y){
if(x-y<0)return x-y+mod;
return x-y;
}
int mul(ll x,ll y){
return x*y%mod;
}
int n,m;
int dp[3023][3023];
signed main(){
ios_base::sync_with_stdio(23^23);cin.tie(0);
cin>>n>>m;
dp[1][m]=1;
for(int i=1;i<=n;i++){
for(int j=0;j<=m;j++){
dp[i+1][j]=sum(dp[i+1][j],dp[i][j]);
if(j>0){
dp[i+1][j-1]=sum(dp[i+1][j-1],mul(dp[i][j],mul(4,j)));
dp[i+2][j-1]=sum(dp[i+2][j-1],mul(dp[i][j],mul(j,n-i)));
}
if(j>1){
int x=j,y=j-1;
if(x&1)y/=2;
else x/=2;
dp[i+1][j-2]=sum(dp[i+1][j-2],mul(dp[i][j],mul(x,y)));
}
}
}
int ans=0;
for(int i=0;i<m;i++){
ans=sum(ans,dp[n+1][i]);
}
cout<<ans<<endl;
}
