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

lis = []
on = 0 + n
count = 0
while on > 0:
  if on & 1 == 1:
    lis.append(count)
  count += 1
  on >>= 1

two = [2]
for _ in range(count-1):
  two.append(two[-1]*two[-1]%mod)

ans = 1
for item in lis:
  ans = ans * two[item] %mod

op = mod-2
invlis = []
count = 0
while op > 0:
  if op & 1 == 1:
    invlis.append(count)
  count += 1
  op >>= 1


def modinv(N):
  if N == 1:
    return 1
  else:
    res = 1
    Nlis = []
    for _ in range(count):
      Nlis.append(N%mod)
      N = N*N%mod
    for item in invlis:
      res = res * Nlis[item] %mod
    return res

ans_a = 1
for k in range(n-a+1, n+1):
  ans_a = ans_a*k%mod
amother = 1
for k in range(2, a+1):
  amother = amother * k % mod
ans_a = ans_a*modinv(amother)%mod

ans_b = 1
for k in range(n-b+1, n+1):
  ans_b = ans_b*k%mod
bmother = 1
for k in range(2, b+1):
  bmother = bmother * k % mod  
ans_b = ans_b*modinv(bmother)%mod

print((ans-ans_a-ans_b-1)%mod) mod = 10**9 +7 mod 10**9 +7 10**9 10 9 7 n, a, b = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split a b lis = [] lis [] on = 0 + n on 0 + n 0 n count = 0 count 0 while on > 0:
  if on & 1 == 1:
    lis.append(count)
  count += 1
  on >>= 1 on > 0 on 0 if on & 1 == 1:
    lis.append(count)
   on & 1 == 1 on & 1 on 1 1 lis.append(count) lis.append lis append count count += 1 count 1 on >>= 1 on 1 two = [2] two [2] 2 for _ in range(count-1):
  two.append(two[-1]*two[-1]%mod) _ range(count-1) range count-1 count 1 two.append(two[-1]*two[-1]%mod) two.append two append two[-1]*two[-1]%mod two[-1]*two[-1] two[-1] two -1 two[-1] two -1 mod ans = 1 ans 1 for item in lis:
  ans = ans * two[item] %mod item lis ans = ans * two[item] %mod ans ans * two[item] %mod ans * two[item] ans two[item] two item mod op = mod-2 op mod-2 mod 2 invlis = [] invlis [] count = 0 count 0 while op > 0:
  if op & 1 == 1:
    invlis.append(count)
  count += 1
  op >>= 1 op > 0 op 0 if op & 1 == 1:
    invlis.append(count)
   op & 1 == 1 op & 1 op 1 1 invlis.append(count) invlis.append invlis append count count += 1 count 1 op >>= 1 op 1 def modinv(N):
  if N == 1:
    return 1
  else:
    res = 1
    Nlis = []
    for _ in range(count):
      Nlis.append(N%mod)
      N = N*N%mod
    for item in invlis:
      res = res * Nlis[item] %mod
    return res modinv if N == 1:
    return 1
  else:
    res = 1
    Nlis = []
    for _ in range(count):
      Nlis.append(N%mod)
      N = N*N%mod
    for item in invlis:
      res = res * Nlis[item] %mod
    return res N == 1 N 1 return 1 1 res = 1 res 1 Nlis = [] Nlis [] for _ in range(count):
      Nlis.append(N%mod)
      N = N*N%mod
     _ range(count) range count Nlis.append(N%mod) Nlis.append Nlis append N%mod N mod N = N*N%mod N N*N%mod N*N N N mod for item in invlis:
      res = res * Nlis[item] %mod
     item invlis res = res * Nlis[item] %mod res res * Nlis[item] %mod res * Nlis[item] res Nlis[item] Nlis item mod return res res N N ans_a = 1 ans_a 1 for k in range(n-a+1, n+1):
  ans_a = ans_a*k%mod k range(n-a+1, n+1) range n-a+1 n-a n a 1 n+1 n 1 ans_a = ans_a*k%mod ans_a ans_a*k%mod ans_a*k ans_a k mod amother = 1 amother 1 for k in range(2, a+1):
  amother = amother * k % mod k range(2, a+1) range 2 a+1 a 1 amother = amother * k % mod amother amother * k % mod amother * k amother k mod ans_a = ans_a*modinv(amother)%mod ans_a ans_a*modinv(amother)%mod ans_a*modinv(amother) ans_a modinv(amother) modinv amother mod ans_b = 1 ans_b 1 for k in range(n-b+1, n+1):
  ans_b = ans_b*k%mod k range(n-b+1, n+1) range n-b+1 n-b n b 1 n+1 n 1 ans_b = ans_b*k%mod ans_b ans_b*k%mod ans_b*k ans_b k mod bmother = 1 bmother 1 for k in range(2, b+1):
  bmother = bmother * k % mod   k range(2, b+1) range 2 b+1 b 1 bmother = bmother * k % mod bmother bmother * k % mod bmother * k bmother k mod ans_b = ans_b*modinv(bmother)%mod ans_b ans_b*modinv(bmother)%mod ans_b*modinv(bmother) ans_b modinv(bmother) modinv bmother mod print((ans-ans_a-ans_b-1)%mod) print (ans-ans_a-ans_b-1)%mod ans-ans_a-ans_b-1 ans-ans_a-ans_b ans-ans_a ans ans_a ans_b 1 mod def modinv(N):
  if N == 1:
    return 1
  else:
    res = 1
    Nlis = []
    for _ in range(count):
      Nlis.append(N%mod)
      N = N*N%mod
    for item in invlis:
      res = res * Nlis[item] %mod
    return res def modinv(N):
  if N == 1:
    return 1
  else:
    res = 1
    Nlis = []
    for _ in range(count):
      Nlis.append(N%mod)
      N = N*N%mod
    for item in invlis:
      res = res * Nlis[item] %mod
    return res modinv count = 0 0 count count += 1 1 count op >>= 1 1 op lis = [] [] lis ans_a = ans_a*k%mod ans_a*k%mod ans_a count += 1 1 count count = 0 0 count ans_b = ans_b*k%mod ans_b*k%mod ans_b two = [2] [2] two ans_b = ans_b*modinv(bmother)%mod ans_b*modinv(bmother)%mod ans_b amother = 1 1 amother ans_a = ans_a*modinv(amother)%mod ans_a*modinv(amother)%mod ans_a bmother = bmother * k % mod bmother * k % mod bmother a, b = map(int, input().split()) map(int, input().split()) a b = map(int, input().split()) map(int, input().split()) b ans = ans * two[item] %mod ans * two[item] %mod ans on >>= 1 1 on ans_b = 1 1 ans_b amother = amother * k % mod amother * k % mod amother op = mod-2 mod-2 op on = 0 + n 0 + n on ans_a = 1 1 ans_a mod = 10**9 +7 10**9 +7 mod n, a, b = map(int, input().split()) map(int, input().split()) n ans = 1 1 ans invlis = [] [] invlis bmother = 1 1 bmother
mod = 10**9 +7
n, a, b = map(int, input().split())

lis = []
on = 0 + n
count = 0
while on > 0:
  if on & 1 == 1:
    lis.append(count)
  count += 1
  on >>= 1

two = [2]
for _ in range(count-1):
  two.append(two[-1]*two[-1]%mod)

ans = 1
for item in lis:
  ans = ans * two[item] %mod

op = mod-2
invlis = []
count = 0
while op > 0:
  if op & 1 == 1:
    invlis.append(count)
  count += 1
  op >>= 1


def modinv(N):
  if N == 1:
    return 1
  else:
    res = 1
    Nlis = []
    for _ in range(count):
      Nlis.append(N%mod)
      N = N*N%mod
    for item in invlis:
      res = res * Nlis[item] %mod
    return res

ans_a = 1
for k in range(n-a+1, n+1):
  ans_a = ans_a*k%mod
amother = 1
for k in range(2, a+1):
  amother = amother * k % mod
ans_a = ans_a*modinv(amother)%mod

ans_b = 1
for k in range(n-b+1, n+1):
  ans_b = ans_b*k%mod
bmother = 1
for k in range(2, b+1):
  bmother = bmother * k % mod  
ans_b = ans_b*modinv(bmother)%mod

print((ans-ans_a-ans_b-1)%mod)