import itertools

import math

n,a,b = list(map(int,input().split()))



mod = 10**9+7



def comb(n, r):

    ans = 1

    for i in range(r):

        ans = ans * (n-i) * pow(i+1, mod-2, mod) % mod

    return ans



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





n,a,b = list(map(int,input().split()))



mod = 10**9+7



def comb(n,r):

	u = 1

	d = 1

	for i in range(n-r+1,n+1):

		u = u*i%mod



	for i in range(1,r+1):

		d = d*i%mod

	D = pow(d,mod-2,mod)



	return u*D%mod



ans = pow(2,n,mod)-1-comb(n,a)-comb(n,b)



print((ans%mod))
import itertools
import math

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


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


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

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


def comb(n, r):
    u = 1
    d = 1
    for i in range(n - r + 1, n + 1):
        u = u * i % mod
    for i in range(1, r + 1):
        d = d * i % mod
    D = pow(d, mod - 2, mod)
    return u * D % mod


ans = pow(2, n, mod) - 1 - comb(n, a) - comb(n, b)
print((ans % mod))

-import itertools -import math - -    ans = 1 -    for i in range(r): -        ans = ans * (n - i) * pow(i + 1, mod - 2, mod) % mod -    return ans +    u = 1 +    d = 1 +    for i in range(n - r + 1, n + 1): +        u = u * i % mod +    for i in range(1, r + 1): +        d = d * i % mod +    D = pow(d, mod - 2, mod) +    return u * D % mod -print(((pow(2, n, mod) - 1 - comb(n, a) - comb(n, b)) % mod)) +ans = pow(2, n, mod) - 1 - comb(n, a) - comb(n, b) +print((ans % mod))