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

mod = 10**9+7

all_combi = pow(2,n,mod)




p = 1
q = 1

for i in range(b):
    
    p *= n-i
    p %= mod
    q *= i+1
    q %= mod
    
    if i==a-1:
        nca = p * pow(q,-1,mod) % mod
        
    if i==b-1:
        ncb = p * pow(q,-1,mod) % mod

        
ans = all_combi -nca -ncb -1
ans %= (10**9+7)
    
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 all_combi = pow(2,n,mod) all_combi pow(2,n,mod) pow 2 n mod p = 1 p 1 q = 1 q 1 for i in range(b):
    
    p *= n-i
    p %= mod
    q *= i+1
    q %= mod
    
    if i==a-1:
        nca = p * pow(q,-1,mod) % mod
        
    if i==b-1:
        ncb = p * pow(q,-1,mod) % mod

         i range(b) range b p *= n-i p n-i n i p %= mod p mod q *= i+1 q i+1 i 1 q %= mod q mod if i==a-1:
        nca = p * pow(q,-1,mod) % mod
        
     i==a-1 i a-1 a 1 nca = p * pow(q,-1,mod) % mod nca p * pow(q,-1,mod) % mod p * pow(q,-1,mod) p pow(q,-1,mod) pow q -1 mod mod if i==b-1:
        ncb = p * pow(q,-1,mod) % mod

         i==b-1 i b-1 b 1 ncb = p * pow(q,-1,mod) % mod ncb p * pow(q,-1,mod) % mod p * pow(q,-1,mod) p pow(q,-1,mod) pow q -1 mod mod ans = all_combi -nca -ncb -1 ans all_combi -nca -ncb -1 all_combi -nca -ncb all_combi -nca all_combi nca ncb 1 ans %= (10**9+7) ans 10**9+7 10**9 10 9 7 print(ans) print ans mod = 10**9+7 10**9+7 mod a,b = map(int,input().split()) map(int,input().split()) a n,a,b = map(int,input().split()) map(int,input().split()) n p *= n-i n-i p b = map(int,input().split()) map(int,input().split()) b q = 1 1 q p %= mod mod p q %= mod mod q all_combi = pow(2,n,mod) pow(2,n,mod) all_combi nca = p * pow(q,-1,mod) % mod p * pow(q,-1,mod) % mod nca ans %= (10**9+7) 10**9+7 ans ncb = p * pow(q,-1,mod) % mod p * pow(q,-1,mod) % mod ncb p = 1 1 p q *= i+1 i+1 q ans = all_combi -nca -ncb -1 all_combi -nca -ncb -1 ans
n,a,b = map(int,input().split())

mod = 10**9+7

all_combi = pow(2,n,mod)




p = 1
q = 1

for i in range(b):
    
    p *= n-i
    p %= mod
    q *= i+1
    q %= mod
    
    if i==a-1:
        nca = p * pow(q,-1,mod) % mod
        
    if i==b-1:
        ncb = p * pow(q,-1,mod) % mod

        
ans = all_combi -nca -ncb -1
ans %= (10**9+7)
    
print(ans)