#include <atcoder/all>
#include <bitset>
#include <fstream>
#include <functional>
#include <iostream>
#include <iomanip>
#include <limits>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdio.h>
#include <stdlib.h>
#include <unordered_map>
#include <unordered_set>
#include <vector>
using namespace std;
using namespace atcoder;

typedef long long ll;
typedef long double ld;
typedef std::pair<int, int> pii;
typedef std::pair<int, ll> pil;
typedef std::pair<ll, int> pli;
typedef std::pair<ll, ll> pll;
typedef std::pair<int, ld> pid;
typedef std::pair<int, std::string> pis;
typedef std::pair<ll, std::string> pls;
typedef std::vector<bool> vb;
typedef std::vector<vb> vvb;
typedef std::vector<int> vi;
typedef std::vector<vi> vvi;
typedef std::vector<vvi> vvvi;
typedef std::vector<vvvi> vvvvi;
typedef std::vector<ll> vl;
typedef std::vector<vl> vvl;
typedef std::vector<vvl> vvvl;
typedef std::vector<vvvl> vvvvl;
typedef std::vector<ld> vd;
typedef std::vector<vd> vvd;
typedef std::vector<std::string> vs;
#define rep(i,n) for(auto i=0; i<n; ++i)
#define repm(i,s,n) for(auto i=s; i<n; ++i)
#define repd(i,n) for(auto i=n-1; i>=0; --i)
#define repdm(i,e,n) for(auto i=n-1; i>=e; --i)
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()

template <class T> inline bool chmax(T& a, T b, int eq = 0) { if (a < b || (a == b && eq)) { a = b; return 1; } return 0; }
template <class T> inline bool chmin(T& a, T b, int eq = 0) { if (a > b || (a == b && eq)) { a = b; return 1; } return 0; }

template <class mint, internal::is_modint_t<mint>* = nullptr> constexpr istream& operator>>(istream& is, mint& x) noexcept {long long v = 0; std::cin >> v; x = v; return is;}
template <class mint, internal::is_modint_t<mint>* = nullptr> constexpr ostream& operator<<(ostream& os, const mint& x) noexcept {os << x.val(); return os;}
inline void _n() { std::cout << std::endl; }
template <class T> inline void _(const T a) { std::cout << a; }
template <class T> inline void _l(const T a) { _(a); _n(); }
template <class T> inline void _s(const T a) { _(a); _(' '); }
template <class T> inline void _v(const std::vector<T> v) { for(auto a : v) _(a); }
template <class T> inline void _vl(const std::vector<T> v) { for(auto a : v) _l(a); }
template <class T> inline void _vs(const std::vector<T> v) { for(auto a : v) _s(a); _n(); }
template <class T> inline void _vvl(const std::vector<std::vector<T>> v) { for(auto a : v) { _v(a); _n(); } }
template <class T> inline void _vvs(const std::vector<std::vector<T>> v) { for(auto a : v) { _vs(a); } }
inline void ynl(const bool b) {_l(b ? "yes" : "no");}
inline void yns(const bool b) {_l(b ? "Yes" : "No");}
inline void ynu(const bool b) {_l(b ? "YES" : "NO");}

constexpr int INF = numeric_limits<int>::max() >> 1;
constexpr long long INF_LL = numeric_limits<long long>::max() >> 1LL;
constexpr long long MOD1 = 1000000007;
constexpr long long MOD9 = 998244353;
using mint1 = atcoder::modint1000000007;
using mint9 = atcoder::modint998244353;

//* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *//

struct cmb_mod {
    using mint = atcoder::modint;

public:
    cmb_mod(long long n, long long m) : _n(n), _mod(m) { init(); }

    long long factorial(long long n) {
        assert(0 <= n && n <= _n);
        mint res = fac[n].val();
        return res.val();
    };

    long long factorial_inv(long long n) {
        assert(0 <= n && n <= _n);
        mint res = finv[n].val();
        return res.val();
    };

    long long permutation(long long n, long long k) {
        assert(0 <= n && n <= _n);
        assert(0 <= k && k <= n);
        mint res = fac[n] * finv[n-k];
        return res.val();
    };

    long long combination(long long n, long long k) {
        assert(0 <= n && n <= _n);
        assert(0 <= k && k <= n);
        mint res = fac[n] * finv[k] * finv[n-k];
        return res.val();
    };

    long long combination_with_repetition (long long n, long long k) {
        return combination(n+k-1, k);
    };

    long long multinomial_coefficient (long long n, std::vector<long long> kv) {
        assert(0 <= n && n <= _n);
        long long ks = 0;
        for(auto a : kv) { assert(0 <= a && a <= _n); ks += a; }
        assert(n == ks);
        mint res = fac[n];
        for(auto a : kv) { res *= finv[a]; }
        return res.val();
    }

private:
    long long _n;
    long long _mod;
    std::vector<mint> fac;
    std::vector<mint> finv;

    void init () {
        assert(0 <= _n);
        assert(1 <= _mod);

        mint::set_mod((int)_mod);
        fac.resize(_n+1, mint(0));
        finv.resize(_n+1, mint(0));

        fac[0] = mint(1);
        for(long long i = 1 ; i <= _n ; ++i) { fac[i] = fac[i-1] * mint(i); }

        finv[_n] = atcoder::inv_mod(fac[_n].val(), _mod);
        for(long long i = _n - 1 ; i > -1 ; --i) { finv[i] = finv[i+1] * (i+1); }
    }
};

void solve() {
    
    int N, M; cin >> N >> M;
    cmb_mod cmb(M, MOD1);
    
    mint1 ans = 0;
    repm(i, N, M+1) {
        ans += cmb.combination(i, N);
    }
    _l(ans);
    
    
    
    
}

//* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *//

int main() {
    
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
    std::cin.tie(0);
    std::cout.tie(0);
    std::ios::sync_with_stdio(false);
    
    solve();
    
    return 0;
}