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

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

nca, ncb = 1, 1

for i in range(b):
    ncb = ncb * (n - i) % mod
    ncb *= pow(i + 1, mod - 2, mod)
    if i + 1 == a:
        nca = ncb

print((ans - (nca + ncb)) % 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 ans = pow(2, n, mod) - 1 ans pow(2, n, mod) - 1 pow(2, n, mod) pow 2 n mod 1 nca, ncb = 1, 1 nca 1 ncb 1 for i in range(b):
    ncb = ncb * (n - i) % mod
    ncb *= pow(i + 1, mod - 2, mod)
    if i + 1 == a:
        nca = ncb i range(b) range b ncb = ncb * (n - i) % mod ncb ncb * (n - i) % mod ncb * (n - i) ncb n - i n i mod ncb *= pow(i + 1, mod - 2, mod) ncb pow(i + 1, mod - 2, mod) pow i + 1 i 1 mod - 2 mod 2 mod if i + 1 == a:
        nca = ncb i + 1 == a i + 1 i 1 a nca = ncb nca ncb print((ans - (nca + ncb)) % mod) print (ans - (nca + ncb)) % mod ans - (nca + ncb) ans nca + ncb nca ncb mod ncb = ncb * (n - i) % mod ncb * (n - i) % mod ncb ncb = 1, 1 1 ncb ncb *= pow(i + 1, mod - 2, mod) pow(i + 1, mod - 2, mod) ncb mod = 10 ** 9 + 7 10 ** 9 + 7 mod a, b = map(int, input().split()) map(int, input().split()) a b = map(int, input().split()) map(int, input().split()) b nca, ncb = 1, 1 1 nca n, a, b = map(int, input().split()) map(int, input().split()) n ans = pow(2, n, mod) - 1 pow(2, n, mod) - 1 ans nca = ncb ncb nca

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

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

nca, ncb = 1, 1

for i in range(b):
    ncb = ncb * (n - i) % mod
    ncb *= pow(i + 1, mod - 2, mod)
    if i + 1 == a:
        nca = ncb

print((ans - (nca + ncb)) % mod)