n, a, b = map( int, input().split() )
mod = 10 ** 9 + 7

N = pow( 2, n, mod ) - 1

def comb( n, r  ):
  c = 1
  m = 1
  r = min( n - r, r )
  for i in range( r ):
    c = c * ( n - i ) % mod
    m = m * ( i + 1 ) % mod
  return c * pow( m, mod - 2, mod ) % mod

A = comb( n, a )
B = comb( n, b )
print( ( N - A - 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 N = pow( 2, n, mod ) - 1 N pow( 2, n, mod ) - 1 pow( 2, n, mod ) pow 2 n mod 1 def comb( n, r  ):
  c = 1
  m = 1
  r = min( n - r, r )
  for i in range( r ):
    c = c * ( n - i ) % mod
    m = m * ( i + 1 ) % mod
  return c * pow( m, mod - 2, mod ) % mod comb c = 1 c 1 m = 1 m 1 r = min( n - r, r ) r min( n - r, r ) min n - r n r r for i in range( r ):
    c = c * ( n - i ) % mod
    m = m * ( i + 1 ) % mod
   i range( r ) range r c = c * ( n - i ) % mod c c * ( n - i ) % mod c * ( n - i ) c n - i n i mod m = m * ( i + 1 ) % mod m m * ( i + 1 ) % mod m * ( i + 1 ) m i + 1 i 1 mod return c * pow( m, mod - 2, mod ) % mod c * pow( m, mod - 2, mod ) % mod c * pow( m, mod - 2, mod ) c pow( m, mod - 2, mod ) pow m mod - 2 mod 2 mod mod n n r r A = comb( n, a ) A comb( n, a ) comb n a B = comb( n, b ) B comb( n, b ) comb n b print( ( N - A - B ) % mod ) print ( N - A - B ) % mod N - A - B N - A N A B mod b = map( int, input().split() ) map( int, input().split() ) b n, a, b = map( int, input().split() ) map( int, input().split() ) n N = pow( 2, n, mod ) - 1 pow( 2, n, mod ) - 1 N A = comb( n, a ) comb( n, a ) A B = comb( n, b ) comb( n, b ) B def comb( n, r  ):
  c = 1
  m = 1
  r = min( n - r, r )
  for i in range( r ):
    c = c * ( n - i ) % mod
    m = m * ( i + 1 ) % mod
  return c * pow( m, mod - 2, mod ) % mod def comb( n, r  ):
  c = 1
  m = 1
  r = min( n - r, r )
  for i in range( r ):
    c = c * ( n - i ) % mod
    m = m * ( i + 1 ) % mod
  return c * pow( m, mod - 2, mod ) % mod comb 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

N = pow( 2, n, mod ) - 1

def comb( n, r  ):
  c = 1
  m = 1
  r = min( n - r, r )
  for i in range( r ):
    c = c * ( n - i ) % mod
    m = m * ( i + 1 ) % mod
  return c * pow( m, mod - 2, mod ) % mod

A = comb( n, a )
B = comb( n, b )
print( ( N - A - B ) % mod )