#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)n;++i)
#define each(a, b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
#define pb push_back
#define show(x) cout <<#x<<" = "<<(x)<<endl
#define spair(p) cout <<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout <<" "<<kbrni;cout<<endl

using namespace std;

typedef pair<int,int>P;

const int MAX_N = 100005;

ll inv[MAX_N],fac[MAX_N],finv[MAX_N];

void make()
{
	fac[0] = fac[1] = 1;
	finv[0] = finv[1] = 1;
	inv[1] = 1;
	for(int i=2;i<MAX_N;i++){
		inv[i] = MOD - inv[MOD%i] * (MOD/i) % MOD;
		fac[i] = fac[i-1] * (ll) i % MOD;
		finv[i] = finv[i-1] * inv[i] % MOD;
	}
}

ll comb(int a,int b)
{
	if(a<b){
		return 0;
	}
	return fac[a] * (finv[b] * finv[a-b] % MOD) % MOD;
}

ll mod_pow(ll a,ll b)
{
    a %= MOD;
    ll res = 1;
    while(b){
        if(b & 1){
            res = res * a % MOD;
        }
        a = a * a %MOD;
        b >>= 1;
    }
    return res;
}


int main()
{
    ll n;
    int m;
    cin >> n >> m;
    if(n < m){
        cout <<"0\n";
        return 0;
    }
    ll ans = 0;
    make();
    rep(i,m){
        ans = (ans + (ll)MOD*MOD + ((i%2)?-1:1)*comb(m,m-i)*mod_pow(m-i,n)) % MOD;
    }
    cout << ans << endl;
    return 0;
}