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

def nCr(n, r):
    r = min(r, n-r)
    num, den = 1, 1
    for i in range(r):
        num = (num * (n-i)) % mod
        den = (den * pow(i+1, mod-2, mod)) % mod
    return num * den % mod

mod = 10**9 + 7
print((pow(2, n, mod) - nCr(n, a) - nCr(n, b) - 1) % mod) n, a, b = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split a b def nCr(n, r):
    r = min(r, n-r)
    num, den = 1, 1
    for i in range(r):
        num = (num * (n-i)) % mod
        den = (den * pow(i+1, mod-2, mod)) % mod
    return num * den % mod nCr r = min(r, n-r) r min(r, n-r) min r n-r n r num, den = 1, 1 num 1 den 1 for i in range(r):
        num = (num * (n-i)) % mod
        den = (den * pow(i+1, mod-2, mod)) % mod
     i range(r) range r num = (num * (n-i)) % mod num (num * (n-i)) % mod num * (n-i) num n-i n i mod den = (den * pow(i+1, mod-2, mod)) % mod den (den * pow(i+1, mod-2, mod)) % mod den * pow(i+1, mod-2, mod) den pow(i+1, mod-2, mod) pow i+1 i 1 mod-2 mod 2 mod mod return num * den % mod num * den % mod num * den num den mod n n r r mod = 10**9 + 7 mod 10**9 + 7 10**9 10 9 7 print((pow(2, n, mod) - nCr(n, a) - nCr(n, b) - 1) % mod) print (pow(2, n, mod) - nCr(n, a) - nCr(n, b) - 1) % mod pow(2, n, mod) - nCr(n, a) - nCr(n, b) - 1 pow(2, n, mod) - nCr(n, a) - nCr(n, b) pow(2, n, mod) - nCr(n, a) pow(2, n, mod) pow 2 n mod nCr(n, a) nCr n a nCr(n, b) nCr n b 1 mod b = map(int, input().split()) map(int, input().split()) b def nCr(n, r):
    r = min(r, n-r)
    num, den = 1, 1
    for i in range(r):
        num = (num * (n-i)) % mod
        den = (den * pow(i+1, mod-2, mod)) % mod
    return num * den % mod def nCr(n, r):
    r = min(r, n-r)
    num, den = 1, 1
    for i in range(r):
        num = (num * (n-i)) % mod
        den = (den * pow(i+1, mod-2, mod)) % mod
    return num * den % mod nCr mod = 10**9 + 7 10**9 + 7 mod n, a, b = map(int, input().split()) map(int, input().split()) n a, b = map(int, input().split()) map(int, input().split()) a
n, a, b = map(int, input().split())

def nCr(n, r):
    r = min(r, n-r)
    num, den = 1, 1
    for i in range(r):
        num = (num * (n-i)) % mod
        den = (den * pow(i+1, mod-2, mod)) % mod
    return num * den % mod

mod = 10**9 + 7
print((pow(2, n, mod) - nCr(n, a) - nCr(n, b) - 1) % mod)