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

def mypow(x, y, mod):
   ans = 1
   while y > 0:
      if bin(y & 1) == bin(1):
         ans *= x % mod
      x *= x % mod
      y = y >> 1
   return ans

def comb(n, r, mod):
   num, denom = 1, 1
   for i in range(1, r+1):
      num = (num*(n+1-i)) % mod
      denom = (denom*i) % mod
   return num * mypow(denom, mod-2, mod) % mod

print((mypow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod)) % 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 mypow(x, y, mod):
   ans = 1
   while y > 0:
      if bin(y & 1) == bin(1):
         ans *= x % mod
      x *= x % mod
      y = y >> 1
   return ans mypow ans = 1 ans 1 while y > 0:
      if bin(y & 1) == bin(1):
         ans *= x % mod
      x *= x % mod
      y = y >> 1
    y > 0 y 0 if bin(y & 1) == bin(1):
         ans *= x % mod
       bin(y & 1) == bin(1) bin(y & 1) bin y & 1 y 1 bin(1) bin 1 ans *= x % mod ans x % mod x mod x *= x % mod x x % mod x mod y = y >> 1 y y >> 1 y 1 return ans ans x x y y mod mod def comb(n, r, mod):
   num, denom = 1, 1
   for i in range(1, r+1):
      num = (num*(n+1-i)) % mod
      denom = (denom*i) % mod
   return num * mypow(denom, mod-2, mod) % mod comb num, denom = 1, 1 num 1 denom 1 for i in range(1, r+1):
      num = (num*(n+1-i)) % mod
      denom = (denom*i) % mod
    i range(1, r+1) range 1 r+1 r 1 num = (num*(n+1-i)) % mod num (num*(n+1-i)) % mod num*(n+1-i) num n+1-i n+1 n 1 i mod denom = (denom*i) % mod denom (denom*i) % mod denom*i denom i mod return num * mypow(denom, mod-2, mod) % mod num * mypow(denom, mod-2, mod) % mod num * mypow(denom, mod-2, mod) num mypow(denom, mod-2, mod) mypow denom mod-2 mod 2 mod mod n n r r mod mod print((mypow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod)) % mod) print (mypow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod)) % mod mypow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod) mypow(2, n, mod) - 1 - comb(n, a, mod) mypow(2, n, mod) - 1 mypow(2, n, mod) mypow 2 n mod 1 comb(n, a, mod) comb n a mod comb(n, b, mod) comb n b mod mod a, b = map(int, input().split()) map(int, input().split()) a mod = 10**9+7 10**9+7 mod def mypow(x, y, mod):
   ans = 1
   while y > 0:
      if bin(y & 1) == bin(1):
         ans *= x % mod
      x *= x % mod
      y = y >> 1
   return ans def mypow(x, y, mod):
   ans = 1
   while y > 0:
      if bin(y & 1) == bin(1):
         ans *= x % mod
      x *= x % mod
      y = y >> 1
   return ans mypow def comb(n, r, mod):
   num, denom = 1, 1
   for i in range(1, r+1):
      num = (num*(n+1-i)) % mod
      denom = (denom*i) % mod
   return num * mypow(denom, mod-2, mod) % mod def comb(n, r, mod):
   num, denom = 1, 1
   for i in range(1, r+1):
      num = (num*(n+1-i)) % mod
      denom = (denom*i) % mod
   return num * mypow(denom, mod-2, mod) % mod comb b = map(int, input().split()) map(int, input().split()) b n, a, b = map(int, input().split()) map(int, input().split()) n
n, a, b = map(int, input().split())
mod = 10**9+7

def mypow(x, y, mod):
   ans = 1
   while y > 0:
      if bin(y & 1) == bin(1):
         ans *= x % mod
      x *= x % mod
      y = y >> 1
   return ans

def comb(n, r, mod):
   num, denom = 1, 1
   for i in range(1, r+1):
      num = (num*(n+1-i)) % mod
      denom = (denom*i) % mod
   return num * mypow(denom, mod-2, mod) % mod

print((mypow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod)) % mod)
