N,A,B = map(int,input().split())

mod = 10**9 + 7
def cmb(n,r,mod):
	a=1
	b=1
	r = min(r,n-r)
	for i in range(r):
		a = a*(n-i)%mod
		b = b*(i+1)%mod
	return a*pow(b,mod-2,mod)%mod

all = pow(2,N,mod) + mod
nCa = cmb(N,A,mod)
nCb = cmb(N,B,mod)

ans = all - nCa - nCb
print((ans-1)%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 def cmb(n,r,mod):
	a=1
	b=1
	r = min(r,n-r)
	for i in range(r):
		a = a*(n-i)%mod
		b = b*(i+1)%mod
	return a*pow(b,mod-2,mod)%mod cmb a=1 a 1 b=1 b 1 r = min(r,n-r) r min(r,n-r) min r n-r n r for i in range(r):
		a = a*(n-i)%mod
		b = b*(i+1)%mod
	 i range(r) range r a = a*(n-i)%mod a a*(n-i)%mod a*(n-i) a n-i n i mod b = b*(i+1)%mod b b*(i+1)%mod b*(i+1) b i+1 i 1 mod return a*pow(b,mod-2,mod)%mod a*pow(b,mod-2,mod)%mod a*pow(b,mod-2,mod) a pow(b,mod-2,mod) pow b mod-2 mod 2 mod mod n n r r mod mod all = pow(2,N,mod) + mod all pow(2,N,mod) + mod pow(2,N,mod) pow 2 N mod mod nCa = cmb(N,A,mod) nCa cmb(N,A,mod) cmb N A mod nCb = cmb(N,B,mod) nCb cmb(N,B,mod) cmb N B mod ans = all - nCa - nCb ans all - nCa - nCb all - nCa all nCa nCb print((ans-1)%mod) print (ans-1)%mod ans-1 ans 1 mod all = pow(2,N,mod) + mod pow(2,N,mod) + mod all B = map(int,input().split()) map(int,input().split()) B ans = all - nCa - nCb all - nCa - nCb ans mod = 10**9 + 7 10**9 + 7 mod nCa = cmb(N,A,mod) cmb(N,A,mod) nCa nCb = cmb(N,B,mod) cmb(N,B,mod) nCb N,A,B = map(int,input().split()) map(int,input().split()) N A,B = map(int,input().split()) map(int,input().split()) A def cmb(n,r,mod):
	a=1
	b=1
	r = min(r,n-r)
	for i in range(r):
		a = a*(n-i)%mod
		b = b*(i+1)%mod
	return a*pow(b,mod-2,mod)%mod def cmb(n,r,mod):
	a=1
	b=1
	r = min(r,n-r)
	for i in range(r):
		a = a*(n-i)%mod
		b = b*(i+1)%mod
	return a*pow(b,mod-2,mod)%mod cmb
N,A,B = map(int,input().split())

mod = 10**9 + 7
def cmb(n,r,mod):
	a=1
	b=1
	r = min(r,n-r)
	for i in range(r):
		a = a*(n-i)%mod
		b = b*(i+1)%mod
	return a*pow(b,mod-2,mod)%mod

all = pow(2,N,mod) + mod
nCa = cmb(N,A,mod)
nCb = cmb(N,B,mod)

ans = all - nCa - nCb
print((ans-1)%mod)