n, a, b = map(int, input().split())
mod = 10**9 + 7
 
def powerDX(n, r, mod):
  if r == 0: return 1
  if r%2 == 0:
    return pow(n*n % mod, r//2, mod) % mod
  if r%2 == 1:
    return n * pow(n, r-1, mod) % mod
 
def combination(n, r, mod=10**9+7):
    n1, r = n+1, min(r, n-r)
    numer = denom = 1
    for i in range(1, r+1):
        numer = numer * (n1-i) % mod
        denom = denom * i % mod
    return numer * pow(denom, mod-2, mod) % mod
 
ans = pow(2, n, mod) - 1
ans -=  combination(n, a, mod)
ans -=  combination(n, b, mod)
ans += 3*mod
ans %= mod
print(ans) 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 powerDX(n, r, mod):
  if r == 0: return 1
  if r%2 == 0:
    return pow(n*n % mod, r//2, mod) % mod
  if r%2 == 1:
    return n * pow(n, r-1, mod) % mod
  powerDX if r == 0: return 1
   r == 0 r 0 if r%2 == 0:
    return pow(n*n % mod, r//2, mod) % mod
   r%2 == 0 r%2 r 2 0 return pow(n*n % mod, r//2, mod) % mod pow(n*n % mod, r//2, mod) % mod pow(n*n % mod, r//2, mod) pow n*n % mod n*n n n mod r//2 r 2 mod mod if r%2 == 1:
    return n * pow(n, r-1, mod) % mod
  r%2 == 1 r%2 r 2 1 return n * pow(n, r-1, mod) % mod n * pow(n, r-1, mod) % mod n * pow(n, r-1, mod) n pow(n, r-1, mod) pow n r-1 r 1 mod mod n n r r mod mod def combination(n, r, mod=10**9+7):
    n1, r = n+1, min(r, n-r)
    numer = denom = 1
    for i in range(1, r+1):
        numer = numer * (n1-i) % mod
        denom = denom * i % mod
    return numer * pow(denom, mod-2, mod) % mod
  combination n1, r = n+1, min(r, n-r) n1 n+1 n 1 r min(r, n-r) min r n-r n r numer = denom = 1 numer 1 = denom = 1 denom 1 for i in range(1, r+1):
        numer = numer * (n1-i) % mod
        denom = denom * i % mod
     i range(1, r+1) range 1 r+1 r 1 numer = numer * (n1-i) % mod numer numer * (n1-i) % mod numer * (n1-i) numer n1-i n1 i mod denom = denom * i % mod denom denom * i % mod denom * i denom i mod return numer * pow(denom, mod-2, mod) % mod numer * pow(denom, mod-2, mod) % mod numer * pow(denom, mod-2, mod) numer pow(denom, mod-2, mod) pow denom mod-2 mod 2 mod mod n n r r mod=10**9+7 mod 10**9+7 10**9 10 9 7 ans = pow(2, n, mod) - 1 ans pow(2, n, mod) - 1 pow(2, n, mod) pow 2 n mod 1 ans -=  combination(n, a, mod) ans combination(n, a, mod) combination n a mod ans -=  combination(n, b, mod) ans combination(n, b, mod) combination n b mod ans += 3*mod ans 3*mod 3 mod ans %= mod ans mod print(ans) print ans b = map(int, input().split()) map(int, input().split()) b ans += 3*mod 3*mod ans mod = 10**9 + 7 10**9 + 7 mod def combination(n, r, mod=10**9+7):
    n1, r = n+1, min(r, n-r)
    numer = denom = 1
    for i in range(1, r+1):
        numer = numer * (n1-i) % mod
        denom = denom * i % mod
    return numer * pow(denom, mod-2, mod) % mod
  def combination(n, r, mod=10**9+7):
    n1, r = n+1, min(r, n-r)
    numer = denom = 1
    for i in range(1, r+1):
        numer = numer * (n1-i) % mod
        denom = denom * i % mod
    return numer * pow(denom, mod-2, mod) % mod
  combination ans -=  combination(n, a, mod) combination(n, a, mod) ans ans %= mod mod ans n, a, b = map(int, input().split()) map(int, input().split()) n def powerDX(n, r, mod):
  if r == 0: return 1
  if r%2 == 0:
    return pow(n*n % mod, r//2, mod) % mod
  if r%2 == 1:
    return n * pow(n, r-1, mod) % mod
  def powerDX(n, r, mod):
  if r == 0: return 1
  if r%2 == 0:
    return pow(n*n % mod, r//2, mod) % mod
  if r%2 == 1:
    return n * pow(n, r-1, mod) % mod
  powerDX ans -=  combination(n, b, mod) combination(n, b, mod) ans ans = pow(2, n, mod) - 1 pow(2, n, mod) - 1 ans a, b = map(int, input().split()) map(int, input().split()) a
n, a, b = map(int, input().split())
mod = 10**9 + 7
 
def powerDX(n, r, mod):
  if r == 0: return 1
  if r%2 == 0:
    return pow(n*n % mod, r//2, mod) % mod
  if r%2 == 1:
    return n * pow(n, r-1, mod) % mod
 
def combination(n, r, mod=10**9+7):
    n1, r = n+1, min(r, n-r)
    numer = denom = 1
    for i in range(1, r+1):
        numer = numer * (n1-i) % mod
        denom = denom * i % mod
    return numer * pow(denom, mod-2, mod) % mod
 
ans = pow(2, n, mod) - 1
ans -=  combination(n, a, mod)
ans -=  combination(n, b, mod)
ans += 3*mod
ans %= mod
print(ans)