from functools import reduce
def comb(n, r, mod=10 ** 9 + 7):
    numerator = reduce(lambda x, y: x * y % mod, [n - r + k + 1 for k in range(r)])
    denominator = reduce(lambda x, y: x * y % mod, [k + 1 for k in range(r)])
    return numerator * pow(denominator, mod - 2, mod) % mod

n, a, b = map(int, input().split())
mod = 1000000007
print((pow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod)) % mod) from functools import reduce def comb(n, r, mod=10 ** 9 + 7):
    numerator = reduce(lambda x, y: x * y % mod, [n - r + k + 1 for k in range(r)])
    denominator = reduce(lambda x, y: x * y % mod, [k + 1 for k in range(r)])
    return numerator * pow(denominator, mod - 2, mod) % mod comb n - r + k + 1 for k in range(r) for k in range(r) k range(r) range r for k in range(r) n - r + k + 1 n - r + k n - r n r k 1 numerator = reduce(lambda x, y: x * y % mod, [n - r + k + 1 for k in range(r)]) numerator reduce(lambda x, y: x * y % mod, [n - r + k + 1 for k in range(r)]) reduce lambda x, y: x * y % mod x * y % mod x * y x y mod x y [n - r + k + 1 for k in range(r)] k + 1 for k in range(r) for k in range(r) k range(r) range r for k in range(r) k + 1 k 1 denominator = reduce(lambda x, y: x * y % mod, [k + 1 for k in range(r)]) denominator reduce(lambda x, y: x * y % mod, [k + 1 for k in range(r)]) reduce lambda x, y: x * y % mod x * y % mod x * y x y mod x y [k + 1 for k in range(r)] return numerator * pow(denominator, mod - 2, mod) % mod numerator * pow(denominator, mod - 2, mod) % mod numerator * pow(denominator, mod - 2, mod) numerator pow(denominator, mod - 2, mod) pow denominator mod - 2 mod 2 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 mod = 1000000007 mod 1000000007 print((pow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod)) % mod) print (pow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod)) % mod pow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod) pow(2, n, mod) - 1 - comb(n, a, mod) pow(2, n, mod) - 1 pow(2, n, mod) pow 2 n mod 1 comb(n, a, mod) comb n a mod comb(n, b, mod) comb n b mod mod mod = 1000000007 1000000007 mod n, a, b = map(int, input().split()) map(int, input().split()) n a, b = map(int, input().split()) map(int, input().split()) a b = map(int, input().split()) map(int, input().split()) b def comb(n, r, mod=10 ** 9 + 7):
    numerator = reduce(lambda x, y: x * y % mod, [n - r + k + 1 for k in range(r)])
    denominator = reduce(lambda x, y: x * y % mod, [k + 1 for k in range(r)])
    return numerator * pow(denominator, mod - 2, mod) % mod def comb(n, r, mod=10 ** 9 + 7):
    numerator = reduce(lambda x, y: x * y % mod, [n - r + k + 1 for k in range(r)])
    denominator = reduce(lambda x, y: x * y % mod, [k + 1 for k in range(r)])
    return numerator * pow(denominator, mod - 2, mod) % mod comb
from functools import reduce
def comb(n, r, mod=10 ** 9 + 7):
    numerator = reduce(lambda x, y: x * y % mod, [n - r + k + 1 for k in range(r)])
    denominator = reduce(lambda x, y: x * y % mod, [k + 1 for k in range(r)])
    return numerator * pow(denominator, mod - 2, mod) % mod

n, a, b = map(int, input().split())
mod = 1000000007
print((pow(2, n, mod) - 1 - comb(n, a, mod) - comb(n, b, mod)) % mod)
