n,a,b = map(int,input().split())
p = 10**9 + 7
def CC(n,k):
  X,Y = 1,1
  for i in range(n-k+1,n+1):
    X = X*i%p
  for j in range(1,k+1):
    Y = Y*j%p
  YY = pow(Y,p-2,p)
  return(X*YY%p)
A = CC(n,a)
B = CC(n,b)
ALL = pow(2,n,p)
ans = (ALL-1-A-B)%p
print(ans) n,a,b = map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split a b p = 10**9 + 7 p 10**9 + 7 10**9 10 9 7 def CC(n,k):
  X,Y = 1,1
  for i in range(n-k+1,n+1):
    X = X*i%p
  for j in range(1,k+1):
    Y = Y*j%p
  YY = pow(Y,p-2,p)
  return(X*YY%p) CC X,Y = 1,1 X 1 Y 1 for i in range(n-k+1,n+1):
    X = X*i%p
   i range(n-k+1,n+1) range n-k+1 n-k n k 1 n+1 n 1 X = X*i%p X X*i%p X*i X i p for j in range(1,k+1):
    Y = Y*j%p
   j range(1,k+1) range 1 k+1 k 1 Y = Y*j%p Y Y*j%p Y*j Y j p YY = pow(Y,p-2,p) YY pow(Y,p-2,p) pow Y p-2 p 2 p return(X*YY%p) X*YY%p X*YY X YY p n n k k A = CC(n,a) A CC(n,a) CC n a B = CC(n,b) B CC(n,b) CC n b ALL = pow(2,n,p) ALL pow(2,n,p) pow 2 n p ans = (ALL-1-A-B)%p ans (ALL-1-A-B)%p ALL-1-A-B ALL-1-A ALL-1 ALL 1 A B p print(ans) print ans ans = (ALL-1-A-B)%p (ALL-1-A-B)%p ans p = 10**9 + 7 10**9 + 7 p b = map(int,input().split()) map(int,input().split()) b n,a,b = map(int,input().split()) map(int,input().split()) n def CC(n,k):
  X,Y = 1,1
  for i in range(n-k+1,n+1):
    X = X*i%p
  for j in range(1,k+1):
    Y = Y*j%p
  YY = pow(Y,p-2,p)
  return(X*YY%p) def CC(n,k):
  X,Y = 1,1
  for i in range(n-k+1,n+1):
    X = X*i%p
  for j in range(1,k+1):
    Y = Y*j%p
  YY = pow(Y,p-2,p)
  return(X*YY%p) CC a,b = map(int,input().split()) map(int,input().split()) a A = CC(n,a) CC(n,a) A ALL = pow(2,n,p) pow(2,n,p) ALL B = CC(n,b) CC(n,b) B
n,a,b = map(int,input().split())
p = 10**9 + 7
def CC(n,k):
  X,Y = 1,1
  for i in range(n-k+1,n+1):
    X = X*i%p
  for j in range(1,k+1):
    Y = Y*j%p
  YY = pow(Y,p-2,p)
  return(X*YY%p)
A = CC(n,a)
B = CC(n,b)
ALL = pow(2,n,p)
ans = (ALL-1-A-B)%p
print(ans)