n,a,b = map(int,input().split())
p = pow(10,9)+7

from functools import reduce
def comb(n,k,p):
    A = reduce(lambda x,y:x*y%p ,[n-k+1+i for i in range(k)])
    B = reduce(lambda x,y:x*y%p ,[i+1 for i in range(k)])
    return A*pow(B,p-2,p)%p

print((pow(2,n,p)-comb(n,a,p)-comb(n,b,p)-1)%p) n,a,b = map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split a b p = pow(10,9)+7 p pow(10,9)+7 pow(10,9) pow 10 9 7 from functools import reduce def comb(n,k,p):
    A = reduce(lambda x,y:x*y%p ,[n-k+1+i for i in range(k)])
    B = reduce(lambda x,y:x*y%p ,[i+1 for i in range(k)])
    return A*pow(B,p-2,p)%p comb n-k+1+i for i in range(k) for i in range(k) i range(k) range k for i in range(k) n-k+1+i n-k+1 n-k n k 1 i A = reduce(lambda x,y:x*y%p ,[n-k+1+i for i in range(k)]) A reduce(lambda x,y:x*y%p ,[n-k+1+i for i in range(k)]) reduce lambda x,y:x*y%p x*y%p x*y x y p x y [n-k+1+i for i in range(k)] i+1 for i in range(k) for i in range(k) i range(k) range k for i in range(k) i+1 i 1 B = reduce(lambda x,y:x*y%p ,[i+1 for i in range(k)]) B reduce(lambda x,y:x*y%p ,[i+1 for i in range(k)]) reduce lambda x,y:x*y%p x*y%p x*y x y p x y [i+1 for i in range(k)] return A*pow(B,p-2,p)%p A*pow(B,p-2,p)%p A*pow(B,p-2,p) A pow(B,p-2,p) pow B p-2 p 2 p p n n k k p p print((pow(2,n,p)-comb(n,a,p)-comb(n,b,p)-1)%p) print (pow(2,n,p)-comb(n,a,p)-comb(n,b,p)-1)%p pow(2,n,p)-comb(n,a,p)-comb(n,b,p)-1 pow(2,n,p)-comb(n,a,p)-comb(n,b,p) pow(2,n,p)-comb(n,a,p) pow(2,n,p) pow 2 n p comb(n,a,p) comb n a p comb(n,b,p) comb n b p 1 p b = map(int,input().split()) map(int,input().split()) b def comb(n,k,p):
    A = reduce(lambda x,y:x*y%p ,[n-k+1+i for i in range(k)])
    B = reduce(lambda x,y:x*y%p ,[i+1 for i in range(k)])
    return A*pow(B,p-2,p)%p def comb(n,k,p):
    A = reduce(lambda x,y:x*y%p ,[n-k+1+i for i in range(k)])
    B = reduce(lambda x,y:x*y%p ,[i+1 for i in range(k)])
    return A*pow(B,p-2,p)%p comb a,b = map(int,input().split()) map(int,input().split()) a n,a,b = map(int,input().split()) map(int,input().split()) n p = pow(10,9)+7 pow(10,9)+7 p
n,a,b = map(int,input().split())
p = pow(10,9)+7

from functools import reduce
def comb(n,k,p):
    A = reduce(lambda x,y:x*y%p ,[n-k+1+i for i in range(k)])
    B = reduce(lambda x,y:x*y%p ,[i+1 for i in range(k)])
    return A*pow(B,p-2,p)%p

print((pow(2,n,p)-comb(n,a,p)-comb(n,b,p)-1)%p)