def cmb(n, r, mod):

    c=1

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

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

    return c



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

MOD = 10**9 + 7

print(((pow(2, n, MOD) - cmb(n, a, MOD) - cmb(n, b, MOD) - 1) % MOD))
n,a,b=list(map(int,input().split()))

mod=10**9+7



def comb(n,r):

    P=1

    R=1

    for i in range(r):

        P=P*(n-i)%mod

        R=R*(r-i)%mod

    return P*pow(R,mod-2,mod)%mod



combN=pow(2,n,mod)-1

print(((combN-comb(n,a)-comb(n,b))%mod))
def cmb(n, r, mod):
    c = 1
    for i in range(1, r + 1):
        c = (c * (n - i + 1) * pow(i, mod - 2, mod)) % mod
    return c


n, a, b = list(map(int, input().split()))
MOD = 10**9 + 7
print(((pow(2, n, MOD) - cmb(n, a, MOD) - cmb(n, b, MOD) - 1) % MOD))

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


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


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

-def cmb(n, r, mod): -    c = 1 -    for i in range(1, r + 1): -        c = (c * (n - i + 1) * pow(i, mod - 2, mod)) % mod -    return c +n, a, b = list(map(int, input().split())) +mod = 10**9 + 7 -n, a, b = list(map(int, input().split())) -MOD = 10**9 + 7 -print(((pow(2, n, MOD) - cmb(n, a, MOD) - cmb(n, b, MOD) - 1) % MOD)) +def comb(n, r): +    P = 1 +    R = 1 +    for i in range(r): +        P = P * (n - i) % mod +        R = R * (r - i) % mod +    return P * pow(R, mod - 2, mod) % mod + + +combN = pow(2, n, mod) - 1 +print(((combN - comb(n, a) - comb(n, b)) % mod))