#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define CHMIN(a,b) a=min((a),(b))
#define CHMAX(a,b) a=max((a),(b))

// mod
const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD

// floating
typedef double Real;
const Real EPS = 1e-11;
#define EQ0(x) (abs(x)<EPS)
#define EQ(a,b) (abs(a-b)<EPS)
typedef complex<Real> P;

ll n,m;

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

ll fact[125252];
ll init(){
  fact[0] = 1;
  FOR(i,1,125252)fact[i]=i*fact[i-1]%MOD;
}
ll comb(ll a,ll b){
  return fact[a]*powmod(fact[b],MOD-2)%MOD*powmod(fact[a-b],MOD-2)%MOD;
}

int main(){
  init();
  cin>>n>>m;
  if(n<m){
    puts("0");
    return 0;
  }
  ll ans = 0;
  ll sign = 1;
  for(int i=m;i>=1;--i){
    ans += sign*powmod(i,n%(MOD-1))%MOD*comb(m,i);
    sign *= -1;
    ans = FIX(ans);
  }
  cout<<ans<<endl;
  return 0;
}