#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
using ll = long long;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define rep2(i,m,n) for (int i = (m); i < (n); ++i)
#define rep3(i,a,b) for (int i = (a); i >= (b); --i)
#define all(x) (x).begin(),(x).end()
inline int popcount(const int x) { return __builtin_popcount(x);}
inline ll popcount(const ll x) { return __builtin_popcountll(x);}
template<class T> void chmin(T &a, const T &b) noexcept { if (b < a) a = b;}
template<class T> void chmax(T &a, const T &b) noexcept { if (a < b) a = b;}
template<class T> void drop(const T &x) { std::cout<<x<<endl; exit(0);}
void debug_out() { std::cout << "\n";}
template<class T, class... Args> void debug_out(const T &x, const Args &... args) { std::cout<<x<< " "; debug_out(args...);}
#ifdef _DEBUG
  #define debug(...) debug_out(__VA_ARGS__)
#else
  #define debug(...) 
#endif

struct InitIO{
  InitIO() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << std::fixed << std::setprecision(15);
  }
}init_io;

const int mod = 1000000007;
// const int mod = 998244353;
struct mint {
  ll x;
  mint(ll x=0):x((x%mod+mod)%mod){}
  mint operator-() const { return mint(-x);}
  mint& operator+=(const mint a) {
    if ((x += a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator-=(const mint a) {
    if ((x += mod-a.x) >= mod) x -= mod;
    return *this;
  }
  mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}
  mint operator+(const mint a) const { return mint(*this) += a;}
  mint operator-(const mint a) const { return mint(*this) -= a;}
  mint operator*(const mint a) const { return mint(*this) *= a;}
  mint pow(ll t) const {
    if (!t) return 1;
    mint a = pow(t>>1);
    a *= a;
    if (t&1) a *= *this;
    return a;
  }
  // for prime mod
  mint inv() const { return pow(mod-2);}
  mint& operator/=(const mint a) { return *this *= a.inv();}
  mint operator/(const mint a) const { return mint(*this) /= a;}
  bool operator==(const mint rhs) const { return x == rhs.x; }
  bool operator!=(const mint rhs) const { return x != rhs.x; }
  bool operator<(const mint &a) const{ return x<a.x;};
};
istream& operator>>(istream& is, mint& a) { return is >> a.x;}
ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}

template<typename ModInt> struct Combination {
  vector<ModInt> fact, ifact;
  Combination(int n):fact(n+1),ifact(n+1) {
    fact[0] = 1;
    for (int i = 1; i <= n; ++i) fact[i] = fact[i-1]*i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i) ifact[i-1] = ifact[i]*i;
  }
  ModInt C(int n, int k) {
    if (k < 0 || n < k) return 0;
    return fact[n]*ifact[k]*ifact[n-k];
  }
  ModInt P(int n, int r) {
    if (r < 0 || n < r) return 0;
    return fact[n]*ifact[n-r];
  }
  ModInt H(int n, int r) {
    if (r < 0 || n < 0) return 0;
    return r == 0 ? 1 : C(n+r-1, r);
  }
  ModInt operator()(int n, int k) { return C(n, k);}
};

int main() {
  int n, m;
  cin >> n >> m;
  Combination<mint> comb(m);
  mint ans = 0;
  rep2(i, n, m+1) {
    ans += comb(i, n);
  }
  cout << ans << endl;
  return 0;
}