Language: C++

#include
  using namespace std;
  #define de_x(x) cout<<"debug_val: "<<x<<endl;
  #define de_ve(x) for(auto it: x) cout<<it<<" ";
  #define rep(i,a,n) for (int i=a;i<n;i++)
  #define _rep(i,a,n) for (int i=a;i<=n;i++)
  #define per(i,a,n) for (int i=n-1;i>=a;i--)
  #define pb push_back
  #define mp make_pair
  #define fi first
  #define se second
  #define SZ(x) ((int)(x).size())
  #define all(x) (x).begin(),(x).end()
  typedef long long ll;
  typedef vector<int> VI;
  typedef pair<int,int> PII;
  typedef double db;
  std::mt19937 mrand(random_device{}());
  int rnd(int x) { return mrand() % x ; }
  const ll mod=1000000007;
  ll ksm(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
  ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
  int _;
  /***********************/

  void run(){
  }
  long Con(int n,int m){
      long x =1,y =1;
      for(int i=1;i<=m;i++){
          x = x*i%mod;
          y = y*i;
      }
      return x *ksm(y,mod-2)%mod;
  }
  int main(){
  //  for(scanf("%d",&_); _;_--) run();   
      long n,a,b;
      cin>> n >> a>> b;
      long ans = ksm(2,n);
      ans -= Con(n,a);
      ans -= Con(n,b);
      ans--;
      ans = (ans%mod +mod)%mod;
      cout<<ans<<endl;
      return 0;
  }

Compiler output:
a.cc:1:9: error: #include expects "FILENAME" or <FILENAME>
    1 | #include
      |         ^
a.cc:15:11: error: 'vector' does not name a type
   15 |   typedef vector<int> VI;
      |           ^~~~~~
a.cc:16:11: error: 'pair' does not name a type
   16 |   typedef pair<int,int> PII;
      |           ^~~~
a.cc:18:8: error: 'mt19937' in namespace 'std' does not name a type
   18 |   std::mt19937 mrand(random_device{}());
      |        ^~~~~~~
a.cc:18:38: error: expected unqualified-id before ')' token
   18 |   std::mt19937 mrand(random_device{}());
      |                                      ^
a.cc: In function 'int rnd(int)':
a.cc:19:27: error: 'mrand' was not declared in this scope; did you mean 'rnd'?
   19 |   int rnd(int x) { return mrand() % x ; }
      |                           ^~~~~
      |                           rnd
a.cc: In function 'll ksm(ll, ll)':
a.cc:21:39: error: 'assert' was not declared in this scope
   21 |   ll ksm(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
      |                                       ^~~~~~
a.cc:1:1: note: 'assert' is defined in header '<cassert>'; this is probably fixable by adding '#include <cassert>'
  +++ |+#include <cassert>
    1 | #include
a.cc: In function 'int main()':
a.cc:39:7: error: 'cin' was not declared in this scope
   39 |       cin>> n >> a>> b;
      |       ^~~
a.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
  +++ |+#include <iostream>
    1 | #include
a.cc:45:7: error: 'cout' was not declared in this scope
   45 |       cout<<ans<<endl;
      |       ^~~~
a.cc:45:7: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:45:18: error: 'endl' was not declared in this scope
   45 |       cout<<ans<<endl;
      |                  ^~~~
a.cc:1:1: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
  +++ |+#include <ostream>
    1 | #include