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

mod = 10**9+7

# (2**n-1)-nCa-nCb

sum_n = pow(2, n, mod)-1
# print(sum_n)
child = 1
mother = 1

for i in range(0, a):
    child *= (n-i)
    child %= mod  # 分子

    mother *= (i+1)
    mother %= mod
# print(mother)
# mod-2はフェルマーの小定理によるchild/mother ->child*(mother**(mod-2)) -2が出てくる理由はhttps://qiita.com/drken/items/3b4fdf0a78e7a138cd9a#3-4-fermat-%E3%81%AE%E5%B0%8F%E5%AE%9A%E7%90%86%E3%81%AB%E3%82%88%E3%82%8B%E9%80%86%E5%85%83%E8%A8%88%E7%AE%97
hate_a = child * pow(mother, mod-2, mod) % mod

child = 1
mother = 1

for i in range(0, b):
    child *= (n-i)
    child %= mod  # 分母

    mother *= (i+1)
    mother %= mod

hate_b = child * pow(mother, mod-2, mod) % mod

print((sum_n-hate_a-hate_b) % 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 sum_n = pow(2, n, mod)-1 sum_n pow(2, n, mod)-1 pow(2, n, mod) pow 2 n mod 1 child = 1 child 1 mother = 1 mother 1 for i in range(0, a):
    child *= (n-i)
    child %= mod  # 分子

    mother *= (i+1)
    mother %= mod
# print(mother)
# mod-2はフェルマーの小定理によるchild/mother ->child*(mother**(mod-2)) -2が出てくる理由はhttps://qiita.com/drken/items/3b4fdf0a78e7a138cd9a#3-4-fermat-%E3%81%AE%E5%B0%8F%E5%AE%9A%E7%90%86%E3%81%AB%E3%82%88%E3%82%8B%E9%80%86%E5%85%83%E8%A8%88%E7%AE%97 i range(0, a) range 0 a child *= (n-i) child n-i n i child %= mod child mod mother *= (i+1) mother i+1 i 1 mother %= mod mother mod hate_a = child * pow(mother, mod-2, mod) % mod hate_a child * pow(mother, mod-2, mod) % mod child * pow(mother, mod-2, mod) child pow(mother, mod-2, mod) pow mother mod-2 mod 2 mod mod child = 1 child 1 mother = 1 mother 1 for i in range(0, b):
    child *= (n-i)
    child %= mod  # 分母

    mother *= (i+1)
    mother %= mod i range(0, b) range 0 b child *= (n-i) child n-i n i child %= mod child mod mother *= (i+1) mother i+1 i 1 mother %= mod mother mod hate_b = child * pow(mother, mod-2, mod) % mod hate_b child * pow(mother, mod-2, mod) % mod child * pow(mother, mod-2, mod) child pow(mother, mod-2, mod) pow mother mod-2 mod 2 mod mod print((sum_n-hate_a-hate_b) % mod) print (sum_n-hate_a-hate_b) % mod sum_n-hate_a-hate_b sum_n-hate_a sum_n hate_a hate_b mod mother %= mod mod mother mother = 1 1 mother child = 1 1 child child %= mod mod child mother %= mod mod mother child *= (n-i) n-i child child *= (n-i) n-i child sum_n = pow(2, n, mod)-1 pow(2, n, mod)-1 sum_n child %= mod mod child mother *= (i+1) i+1 mother n, a, b = map(int, input().split()) map(int, input().split()) n hate_b = child * pow(mother, mod-2, mod) % mod child * pow(mother, mod-2, mod) % mod hate_b mother = 1 1 mother mod = 10**9+7 10**9+7 mod a, b = map(int, input().split()) map(int, input().split()) a hate_a = child * pow(mother, mod-2, mod) % mod child * pow(mother, mod-2, mod) % mod hate_a b = map(int, input().split()) map(int, input().split()) b child = 1 1 child mother *= (i+1) i+1 mother

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

mod = 10**9+7

# (2**n-1)-nCa-nCb

sum_n = pow(2, n, mod)-1
# print(sum_n)
child = 1
mother = 1

for i in range(0, a):
    child *= (n-i)
    child %= mod  # 分子

    mother *= (i+1)
    mother %= mod
# print(mother)
# mod-2はフェルマーの小定理によるchild/mother ->child*(mother**(mod-2)) -2が出てくる理由はhttps://qiita.com/drken/items/3b4fdf0a78e7a138cd9a#3-4-fermat-%E3%81%AE%E5%B0%8F%E5%AE%9A%E7%90%86%E3%81%AB%E3%82%88%E3%82%8B%E9%80%86%E5%85%83%E8%A8%88%E7%AE%97
hate_a = child * pow(mother, mod-2, mod) % mod

child = 1
mother = 1

for i in range(0, b):
    child *= (n-i)
    child %= mod  # 分母

    mother *= (i+1)
    mother %= mod

hate_b = child * pow(mother, mod-2, mod) % mod

print((sum_n-hate_a-hate_b) % mod)
