#include<bits/stdc++.h>
#define MOD ((long long)1e9+7)
using namespace std;
int n,m;
long long dp[3005][3005];
int main() {
cin >> n >> m;
dp[0][0] = 1LL;
for(int i=0; i<n; i++) {
for(int j=0; j<=m; j++) {
if(j+2<=m) {
dp[i+1][j+2] += (((m-j)*(m-j-1LL)/2)%MOD) * dp[i][j];
dp[i+1][j+2] %= MOD;
}
if(j<m) {
dp[i+1][j+1] += dp[i][j] * (m-j) * 4LL;
dp[i+1][j+1] %= MOD;
}
if(i<n-1) {
dp[i+2][j+1] += dp[i][j] * (((long long)m-j)*(i+1))%MOD;
}
}
for(int j=0; j<=m; j++) {
dp[i+1][j] += dp[i][j];
}
}
long long ans = 0;
for(int j=1; j<=m; j++) {
ans += dp[n][j];
}
cout << ans%MOD << endl;
}
