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

fa = pow(fa, mod-2, mod)
fb = pow(fb, mod-2, mod)

for i in range(a):
    fa *= n - i
    fa %= mod
for i in range(b):
    fb *= n - i
    fb %= mod

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

fa = pow(fa, mod-2, mod)
fb = pow(fb, mod-2, mod)

for i in range(a):
    fa *= n - i
    fa %= mod
for i in range(b):
    fb *= n - i
    fb %= mod

print((ans - fa - fb) % mod)