// includes
#include <bits/stdc++.h>

// macros
#define ll long long int
#define pb emplace_back
#define mk make_pair
#define pq priority_queue
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define irep(itr, st) for(auto itr = (st).begin(); itr != (st).end(); ++itr)
#define irrep(itr, st) for(auto itr = (st).rbegin(); itr != (st).rend(); ++itr)
#define vrep(v, i) for(int i = 0; i < (v).size(); i++)
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())
#define FI first
#define SE second
#define dump(a, n) for(int i = 0; i < n; i++)cout << a[i] << "\n "[i + 1 != n];
#define dump2(a, n, m) for(int i = 0; i < n; i++)for(int j = 0; j < m; j++)cout << a[i][j] << "\n "[j + 1 != m];
#define bit(n) (1LL<<(n))
#define INT(n) int n; cin >> n;
#define LL(n) ll n; cin >> n;
#define DOUBLE(n) double n; cin >> n;
using namespace std;

template <class T>bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;}
template <class T>bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec){for(auto &v: vec)is >> v; return is;}
template <typename T> ostream &operator<<(ostream &os, const vector<T>& vec){for(int i = 0; i < vec.size(); i++){ os << vec[i]; if(i + 1 != vec.size())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){os << p.first << " " << p.second; return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}

//  types
typedef pair<int, int> P;
typedef pair<ll, int> Pl;
typedef pair<ll, ll> Pll;
typedef pair<double, double> Pd;
typedef complex<double> cd;

// constants
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1e9 + 7;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};

// solve
ll r[102] = {1, 682498929, 491101308, 76479948, 723816384, 67347853, 27368307, 625544428, 199888908, 888050723, 927880474, 281863274, 661224977, 623534362, 970055531, 261384175, 195888993, 66404266, 547665832, 109838563, 933245637, 724691727, 368925948, 268838846, 136026497, 112390913, 135498044, 217544623, 419363534, 500780548, 668123525, 128487469, 30977140, 522049725, 309058615, 386027524, 189239124, 148528617, 940567523, 917084264, 429277690, 996164327, 358655417, 568392357, 780072518, 462639908, 275105629, 909210595, 99199382, 703397904, 733333339, 97830135, 608823837, 256141983, 141827977, 696628828, 637939935, 811575797, 848924691, 131772368, 724464507, 272814771, 326159309, 456152084, 903466878, 92255682, 769795511, 373745190, 606241871, 825871994, 957939114, 435887178, 852304035, 663307737, 375297772, 217598709, 624148346, 671734977, 624500515, 748510389, 203191898, 423951674, 629786193, 672850561, 814362881, 823845496, 116667533, 256473217, 627655552, 245795606, 586445753, 172114298, 193781724, 778983779, 83868974, 315103615, 965785236, 492741665, 377329025, 847549272, 698611116, 1000000006};

constexpr int MOD = 1000000007;

// + - * / ^
int mod_iroiro(int a)
{
    int res = a % MOD;
    if(res < 0) {
        return res + MOD;
    }
    return res;
}
int mul_mod(int a, int b)
{
    ll res = ((ll)a * (ll)b) % MOD;
    return mod_iroiro((int)res);
}
int pow_mod(int a, int b)
{
    ll res = 1;
    while (b > 0) {
        if(b & 1) {
            res = res * (ll)a % (ll)MOD;
        }
        a = mul_mod(a, a);
        b >>= 1;
    }
    return (int)res;
}
int inv_mod(int a)
{
    return pow_mod(a, MOD - 2);
}
int div_mod(int a, int b)
{
    return mul_mod(a, inv_mod(b));
}

// ! C
constexpr int FAC_MAX = 3000001;
ll fac[FAC_MAX], finv[FAC_MAX], inv[FAC_MAX];
void com_init()
{
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for (int i = 2; i < FAC_MAX; i++){
        fac[i] = fac[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD%i] * (MOD / i) % MOD;
        finv[i] = finv[i - 1] * inv[i] % MOD;
    }
}
ll com_mod(int a, int b){
    if (a < b) return 0;
    if (a < 0 || b < 0) return 0;
    return fac[a] * (finv[b] * finv[a - b] % MOD) % MOD;
}


int main(int argc, char const* argv[])
{
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(20);
  LL(n);
  ll base = 10000000;
  int at = n / base;
  ll res = r[at];
  for(ll i = at * base + 1; i <= n; i++){
    res = res * i % mod;
  }
  LL(a);
  at = a / base;
  ll resa = r[at];
  for(ll i = at * base + 1; i <= a; i++){
    resa = resa * i % mod;
  }
  at = (n - a) / base;
  ll resan = r[at];
  for(ll i = at * base + 1; i <= n-a; i++){
    resan = resan * i % mod;
  }
  LL(b);
  at = b / base;
  ll resb = r[at];
  for(ll i = at * base + 1; i <= b; i++){
    resb = resb * i % mod;
  }
//   cout << n - a << "\n";
  at = (n - b) / base;
  ll resbn = r[at];
  for(ll i = at * base + 1; i <= n-b; i++){
    resbn = resbn * i % mod;
  }


  int ans = mod_iroiro( pow_mod(2, n) - 1 );
  ans = mod_iroiro(ans - div_mod(div_mod(res, resa), resan) - div_mod(div_mod(res, resb), resbn));
  cout << ans << "\n";
//   cout << res << endl;
//   cout << resa << " " << resan << endl;
//   cout << resb << " " << resbn << endl;
//   cout << div_mod(div_mod(res, resa), resan) << endl;
//   cout << div_mod(div_mod(res, resa), resan) << endl;
  
  return 0;
}

Measured memory_bytes: 256