n,a,b=map(int,input().split())
MOD=10**9+7
def inv(a):
  return pow(a,MOD-2,MOD)
def choose(n,r):
  if r==0 or r==n:
    return 1
  else:
    A=B=1
    for i in range(r):
      A=A*(n-i)%MOD
      B=B*(i+1)%MOD
    return A*inv(B)%MOD
print((pow(2,n,MOD)-1-choose(n,a)-choose(n,b))%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 inv(a):
  return pow(a,MOD-2,MOD) inv return pow(a,MOD-2,MOD) pow(a,MOD-2,MOD) pow a MOD-2 MOD 2 MOD a a def choose(n,r):
  if r==0 or r==n:
    return 1
  else:
    A=B=1
    for i in range(r):
      A=A*(n-i)%MOD
      B=B*(i+1)%MOD
    return A*inv(B)%MOD choose if r==0 or r==n:
    return 1
  else:
    A=B=1
    for i in range(r):
      A=A*(n-i)%MOD
      B=B*(i+1)%MOD
    return A*inv(B)%MOD r==0 or r==n r==0 r 0 r==n r n return 1 1 A=B=1 A 1 =B=1 B 1 for i in range(r):
      A=A*(n-i)%MOD
      B=B*(i+1)%MOD
     i range(r) range r A=A*(n-i)%MOD A A*(n-i)%MOD A*(n-i) A n-i n i MOD B=B*(i+1)%MOD B B*(i+1)%MOD B*(i+1) B i+1 i 1 MOD return A*inv(B)%MOD A*inv(B)%MOD A*inv(B) A inv(B) inv B MOD n n r r print((pow(2,n,MOD)-1-choose(n,a)-choose(n,b))%MOD) print (pow(2,n,MOD)-1-choose(n,a)-choose(n,b))%MOD pow(2,n,MOD)-1-choose(n,a)-choose(n,b) pow(2,n,MOD)-1-choose(n,a) pow(2,n,MOD)-1 pow(2,n,MOD) pow 2 n MOD 1 choose(n,a) choose n a choose(n,b) choose n b MOD n,a,b=map(int,input().split()) map(int,input().split()) n b=map(int,input().split()) map(int,input().split()) b def choose(n,r):
  if r==0 or r==n:
    return 1
  else:
    A=B=1
    for i in range(r):
      A=A*(n-i)%MOD
      B=B*(i+1)%MOD
    return A*inv(B)%MOD def choose(n,r):
  if r==0 or r==n:
    return 1
  else:
    A=B=1
    for i in range(r):
      A=A*(n-i)%MOD
      B=B*(i+1)%MOD
    return A*inv(B)%MOD choose def inv(a):
  return pow(a,MOD-2,MOD) def inv(a):
  return pow(a,MOD-2,MOD) inv a,b=map(int,input().split()) map(int,input().split()) a MOD=10**9+7 10**9+7 MOD
n,a,b=map(int,input().split())
MOD=10**9+7
def inv(a):
  return pow(a,MOD-2,MOD)
def choose(n,r):
  if r==0 or r==n:
    return 1
  else:
    A=B=1
    for i in range(r):
      A=A*(n-i)%MOD
      B=B*(i+1)%MOD
    return A*inv(B)%MOD
print((pow(2,n,MOD)-1-choose(n,a)-choose(n,b))%MOD)