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#include<bits/stdc++.h>
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("trapv")

#define st first
#define nd second
#define pb(x) push_back(x)
#define pp(x) pop_back(x)
#define mp(a, b) make_pair(a, b)
#define all(x) (x).begin(), (x).end()
#define rev(x) reverse(all(x))
#define sor(x) sort(all(x))
#define sz(x) (int)(x).size()
#define rsz(x) resize(x)

using namespace std;

///~~~~~~~~~~~~~~~~~~~~~~~~~~

void debug(){cerr<<"\n";}
template <typename H, typename... T>
void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);}
#define deb(x...) cerr<<#x<<" = ";debug(x);

///~~~~~~~~~~~~~~~~~~~~~~~~~

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii > vii;
typedef vector<ll> vl;
typedef vector<pll> vll;
typedef string str;

#define BOOST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

const int N=3005, INF=1e9+5, mod=1e9+7;
ll dp[N][N][2];
int main(){
	BOOST;
	int n, m;
	cin>>n>>m;
	dp[1][1][0]=m;
	for(int i=1; i<=n; i++){
		for(int j=1; j<=i; j++){
			dp[i][j][0]%=mod;
			dp[i][j][1]%=mod;
			dp[i+1][j][0]+=((m-j)*1ll*dp[i][j][0])%mod;
			dp[i+1][j+1][0]+=((m-j)*1ll*dp[i][j][1])%mod;
			dp[i+1][j][1]+=(j*1ll*dp[i][j][0])%mod;
			dp[i+1][j][1]+=(j*1ll*dp[i][j][1])%mod;
			//deb(i, j, dp[i][j][0], dp[i][j][1]);
		}
	}
	ll ans=0;
	for(int i=1; i<=n; i++)ans+=dp[n][i][1];
		cout<<ans%mod;
}