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#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
typedef long double LD;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;

#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()

template<typename _T> inline void _DBG(const char *s, _T x) { cerr << s << " = " << x << "\n"; }
template<typename _T, typename... args> void _DBG(const char *s, _T x, args... a) { while(*s != ',') cerr << *s++; cerr << " = " << x << ','; _DBG(s + 1, a...); }

#ifdef LOCAL
#define _upgrade ios_base::sync_with_stdio(0);
#define DBG(...) _DBG(#__VA_ARGS__, __VA_ARGS__)
#else
#define _upgrade ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define DBG(...) (__VA_ARGS__)
#define cerr if(0) cout
#endif

// ********************** CODE ********************** //

const int N = 3005;
const int M = 1e9 + 7;

LL n, m, dp[2][N][2];

int main()
{
    _upgrade
    
    cin >> n >> m;
    
    dp[0][0][1] = 1;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < i; j++)
        {
            dp[(i + 1) & 1][j][0] = 0;
            dp[(i + 1) & 1][j][1] = 0;
        }
        for (LL j = 0; j <= i; j++)
        {
            dp[(i + 1) & 1][j][1] = (dp[(i + 1) & 1][j][1] + dp[i & 1][j][0] * j) % M;
            dp[(i + 1) & 1][j][0] = (dp[(i + 1) & 1][j][0] + dp[i & 1][j][0] * (m - j)) % M;

            dp[(i + 1) & 1][j][1] = (dp[(i + 1) & 1][j][1] + dp[i & 1][j][1] * j) % M;
            dp[(i + 1) & 1][j + 1][0] = (dp[(i + 1) & 1][j + 1][0] + dp[i & 1][j][1] * (m - j)) % M;
        }
    }

    LL ans = 0;
    for (int j = 0; j <= n; j++)
        ans = (ans + dp[n & 1][j][1]) % M;
    
    cout << ans << "\n";
    return 0;
}