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

mod = 10 ** 9 + 7

ans = pow(2, n, mod) - 1
for i in [a, b]:
    num = 1
    den = 1
    for p in range(n, n-i, -1):
        num = num * p % mod
    for q in range(1, i+1):
        den = den * q % mod
    cmb = num * pow(den, mod-2, mod) % mod
    ans -= cmb
    ans %= mod
print(ans) 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 for i in [a, b]:
    num = 1
    den = 1
    for p in range(n, n-i, -1):
        num = num * p % mod
    for q in range(1, i+1):
        den = den * q % mod
    cmb = num * pow(den, mod-2, mod) % mod
    ans -= cmb
    ans %= mod i [a, b] a b num = 1 num 1 den = 1 den 1 for p in range(n, n-i, -1):
        num = num * p % mod
     p range(n, n-i, -1) range n n-i n i -1 num = num * p % mod num num * p % mod num * p num p mod for q in range(1, i+1):
        den = den * q % mod
     q range(1, i+1) range 1 i+1 i 1 den = den * q % mod den den * q % mod den * q den q mod cmb = num * pow(den, mod-2, mod) % mod cmb num * pow(den, mod-2, mod) % mod num * pow(den, mod-2, mod) num pow(den, mod-2, mod) pow den mod-2 mod 2 mod mod ans -= cmb ans cmb ans %= mod ans mod print(ans) print ans ans %= mod mod ans mod = 10 ** 9 + 7 10 ** 9 + 7 mod num = 1 1 num cmb = num * pow(den, mod-2, mod) % mod num * pow(den, mod-2, mod) % mod cmb n, a, b = map(int, input().split()) map(int, input().split()) n a, b = map(int, input().split()) map(int, input().split()) a num = num * p % mod num * p % mod num den = den * q % mod den * q % mod den den = 1 1 den ans = pow(2, n, mod) - 1 pow(2, n, mod) - 1 ans b = map(int, input().split()) map(int, input().split()) b ans -= cmb cmb ans
n, a, b = map(int, input().split())

mod = 10 ** 9 + 7

ans = pow(2, n, mod) - 1
for i in [a, b]:
    num = 1
    den = 1
    for p in range(n, n-i, -1):
        num = num * p % mod
    for q in range(1, i+1):
        den = den * q % mod
    cmb = num * pow(den, mod-2, mod) % mod
    ans -= cmb
    ans %= mod
print(ans)