n, a, b = map(int, input().split())
if a > b: a, b = b, a
mod = 10 ** 9 + 7
tmp = 1

C = n
ans = 0
if a == 1: Ca = n
for r in range(1, n + 1):
    C = (((C * (n - r)) % mod )* pow(r + 1, mod - 2, mod)) % mod
    if r == a - 1:
        Ca = C
    if r == b - 1:
        Cb = C
        break

print((pow(2, n, mod) - Ca - Cb - 1) % mod) n, a, b = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split a b if a > b: a, b = b, a a > b a b mod = 10 ** 9 + 7 mod 10 ** 9 + 7 10 ** 9 10 9 7 tmp = 1 tmp 1 C = n C n ans = 0 ans 0 if a == 1: Ca = n a == 1 a 1 for r in range(1, n + 1):
    C = (((C * (n - r)) % mod )* pow(r + 1, mod - 2, mod)) % mod
    if r == a - 1:
        Ca = C
    if r == b - 1:
        Cb = C
        break r range(1, n + 1) range 1 n + 1 n 1 C = (((C * (n - r)) % mod )* pow(r + 1, mod - 2, mod)) % mod C (((C * (n - r)) % mod )* pow(r + 1, mod - 2, mod)) % mod ((C * (n - r)) % mod )* pow(r + 1, mod - 2, mod) (C * (n - r)) % mod C * (n - r) C n - r n r mod pow(r + 1, mod - 2, mod) pow r + 1 r 1 mod - 2 mod 2 mod mod if r == a - 1:
        Ca = C
     r == a - 1 r a - 1 a 1 Ca = C Ca C if r == b - 1:
        Cb = C
        break r == b - 1 r b - 1 b 1 Cb = C Cb C break print((pow(2, n, mod) - Ca - Cb - 1) % mod) print (pow(2, n, mod) - Ca - Cb - 1) % mod pow(2, n, mod) - Ca - Cb - 1 pow(2, n, mod) - Ca - Cb pow(2, n, mod) - Ca pow(2, n, mod) pow 2 n mod Ca Cb 1 mod C = (((C * (n - r)) % mod )* pow(r + 1, mod - 2, mod)) % mod (((C * (n - r)) % mod )* pow(r + 1, mod - 2, mod)) % mod C a, b = map(int, input().split()) map(int, input().split()) a tmp = 1 1 tmp n, a, b = map(int, input().split()) map(int, input().split()) n Cb = C C Cb mod = 10 ** 9 + 7 10 ** 9 + 7 mod ans = 0 0 ans b = map(int, input().split()) map(int, input().split()) b C = n n C Ca = C C Ca
n, a, b = map(int, input().split())
if a > b: a, b = b, a
mod = 10 ** 9 + 7
tmp = 1

C = n
ans = 0
if a == 1: Ca = n
for r in range(1, n + 1):
    C = (((C * (n - r)) % mod )* pow(r + 1, mod - 2, mod)) % mod
    if r == a - 1:
        Ca = C
    if r == b - 1:
        Cb = C
        break

print((pow(2, n, mod) - Ca - Cb - 1) % mod)
