n,a,b=map(int,input().split())
mod=10**9+7
def comb(n,k,mod):
  if k>n-k:
    k=n-k
  c=1
  for i in range(n-k+1,n+1):
    c*=i
    c%=mod
  d=1  
  for i in range(1,k+1):
    d*=i
    d%=mod
  return (c*pow(d,mod-2,mod))%mod

ans=pow(2,n,mod)-1-comb(n,a,mod)-comb(n,b,mod)
print(ans%mod) n,a,b=map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split a b mod=10**9+7 mod 10**9+7 10**9 10 9 7 def comb(n,k,mod):
  if k>n-k:
    k=n-k
  c=1
  for i in range(n-k+1,n+1):
    c*=i
    c%=mod
  d=1  
  for i in range(1,k+1):
    d*=i
    d%=mod
  return (c*pow(d,mod-2,mod))%mod comb if k>n-k:
    k=n-k
   k>n-k k n-k n k k=n-k k n-k n k c=1 c 1 for i in range(n-k+1,n+1):
    c*=i
    c%=mod
   i range(n-k+1,n+1) range n-k+1 n-k n k 1 n+1 n 1 c*=i c i c%=mod c mod d=1 d 1 for i in range(1,k+1):
    d*=i
    d%=mod
   i range(1,k+1) range 1 k+1 k 1 d*=i d i d%=mod d mod return (c*pow(d,mod-2,mod))%mod (c*pow(d,mod-2,mod))%mod c*pow(d,mod-2,mod) c pow(d,mod-2,mod) pow d mod-2 mod 2 mod mod n n k k mod mod ans=pow(2,n,mod)-1-comb(n,a,mod)-comb(n,b,mod) ans pow(2,n,mod)-1-comb(n,a,mod)-comb(n,b,mod) pow(2,n,mod)-1-comb(n,a,mod) pow(2,n,mod)-1 pow(2,n,mod) pow 2 n mod 1 comb(n,a,mod) comb n a mod comb(n,b,mod) comb n b mod print(ans%mod) print ans%mod ans mod mod=10**9+7 10**9+7 mod def comb(n,k,mod):
  if k>n-k:
    k=n-k
  c=1
  for i in range(n-k+1,n+1):
    c*=i
    c%=mod
  d=1  
  for i in range(1,k+1):
    d*=i
    d%=mod
  return (c*pow(d,mod-2,mod))%mod def comb(n,k,mod):
  if k>n-k:
    k=n-k
  c=1
  for i in range(n-k+1,n+1):
    c*=i
    c%=mod
  d=1  
  for i in range(1,k+1):
    d*=i
    d%=mod
  return (c*pow(d,mod-2,mod))%mod comb a,b=map(int,input().split()) map(int,input().split()) a b=map(int,input().split()) map(int,input().split()) b n,a,b=map(int,input().split()) map(int,input().split()) n ans=pow(2,n,mod)-1-comb(n,a,mod)-comb(n,b,mod) pow(2,n,mod)-1-comb(n,a,mod)-comb(n,b,mod) ans
n,a,b=map(int,input().split())
mod=10**9+7
def comb(n,k,mod):
  if k>n-k:
    k=n-k
  c=1
  for i in range(n-k+1,n+1):
    c*=i
    c%=mod
  d=1  
  for i in range(1,k+1):
    d*=i
    d%=mod
  return (c*pow(d,mod-2,mod))%mod

ans=pow(2,n,mod)-1-comb(n,a,mod)-comb(n,b,mod)
print(ans%mod)
