def per(n, r, mod=10**9+7):  # 順列数
    per = 1
    for i in range(r):
        per = per*(n-i) % mod
    return per
 
 
def com(n, r, mod=10**9+7):  # 組み合わせ数
    bunshi = per(n, r, mod)
    bunbo = 1
    for i in range(1, r+1):
        bunbo = bunbo*i % mod
    return bunshi*pow(bunbo, -1, mod)%mod
 
 
n, a, b = map(int, input().split())
 
ans = pow(2,n,10**9+7)
 
print((ans-com(n,a)-com(n,b)-1)%(10**9+7)) def per(n, r, mod=10**9+7):  # 順列数
    per = 1
    for i in range(r):
        per = per*(n-i) % mod
    return per
 
  per per = 1 per 1 for i in range(r):
        per = per*(n-i) % mod
     i range(r) range r per = per*(n-i) % mod per per*(n-i) % mod per*(n-i) per n-i n i mod return per per n n r r mod=10**9+7 mod 10**9+7 10**9 10 9 7 def com(n, r, mod=10**9+7):  # 組み合わせ数
    bunshi = per(n, r, mod)
    bunbo = 1
    for i in range(1, r+1):
        bunbo = bunbo*i % mod
    return bunshi*pow(bunbo, -1, mod)%mod
 
  com bunshi = per(n, r, mod) bunshi per(n, r, mod) per n r mod bunbo = 1 bunbo 1 for i in range(1, r+1):
        bunbo = bunbo*i % mod
     i range(1, r+1) range 1 r+1 r 1 bunbo = bunbo*i % mod bunbo bunbo*i % mod bunbo*i bunbo i mod return bunshi*pow(bunbo, -1, mod)%mod bunshi*pow(bunbo, -1, mod)%mod bunshi*pow(bunbo, -1, mod) bunshi pow(bunbo, -1, mod) pow bunbo -1 mod mod n n r r 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 ans = pow(2,n,10**9+7) ans pow(2,n,10**9+7) pow 2 n 10**9+7 10**9 10 9 7 print((ans-com(n,a)-com(n,b)-1)%(10**9+7)) print (ans-com(n,a)-com(n,b)-1)%(10**9+7) ans-com(n,a)-com(n,b)-1 ans-com(n,a)-com(n,b) ans-com(n,a) ans com(n,a) com n a com(n,b) com n b 1 10**9+7 10**9 10 9 7 def per(n, r, mod=10**9+7):  # 順列数
    per = 1
    for i in range(r):
        per = per*(n-i) % mod
    return per
 
  def per(n, r, mod=10**9+7):  # 順列数
    per = 1
    for i in range(r):
        per = per*(n-i) % mod
    return per
 
  per a, b = map(int, input().split()) map(int, input().split()) a n, a, b = map(int, input().split()) map(int, input().split()) n b = map(int, input().split()) map(int, input().split()) b ans = pow(2,n,10**9+7) pow(2,n,10**9+7) ans def com(n, r, mod=10**9+7):  # 組み合わせ数
    bunshi = per(n, r, mod)
    bunbo = 1
    for i in range(1, r+1):
        bunbo = bunbo*i % mod
    return bunshi*pow(bunbo, -1, mod)%mod
 
  def com(n, r, mod=10**9+7):  # 組み合わせ数
    bunshi = per(n, r, mod)
    bunbo = 1
    for i in range(1, r+1):
        bunbo = bunbo*i % mod
    return bunshi*pow(bunbo, -1, mod)%mod
 
  com
def per(n, r, mod=10**9+7):  # 順列数
    per = 1
    for i in range(r):
        per = per*(n-i) % mod
    return per
 
 
def com(n, r, mod=10**9+7):  # 組み合わせ数
    bunshi = per(n, r, mod)
    bunbo = 1
    for i in range(1, r+1):
        bunbo = bunbo*i % mod
    return bunshi*pow(bunbo, -1, mod)%mod
 
 
n, a, b = map(int, input().split())
 
ans = pow(2,n,10**9+7)
 
print((ans-com(n,a)-com(n,b)-1)%(10**9+7))