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

def modinv(n):
    return pow(n, M-2, M)

def comb(n, r):
    num = denom = 1
    for i in range(1,r+1):
        num = (num*(n+1-i))%M
        denom = (denom*i)%M
    return num * modinv(denom) % M

print((pow(2, n, M) - comb(n, a) - comb(n, b) - 1) % M) M = 10**9 + 7 M 10**9 + 7 10**9 10 9 7 n,a,b = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split a b def modinv(n):
    return pow(n, M-2, M) modinv return pow(n, M-2, M) pow(n, M-2, M) pow n M-2 M 2 M n n def comb(n, r):
    num = denom = 1
    for i in range(1,r+1):
        num = (num*(n+1-i))%M
        denom = (denom*i)%M
    return num * modinv(denom) % M comb num = denom = 1 num 1 = denom = 1 denom 1 for i in range(1,r+1):
        num = (num*(n+1-i))%M
        denom = (denom*i)%M
     i range(1,r+1) range 1 r+1 r 1 num = (num*(n+1-i))%M num (num*(n+1-i))%M num*(n+1-i) num n+1-i n+1 n 1 i M denom = (denom*i)%M denom (denom*i)%M denom*i denom i M return num * modinv(denom) % M num * modinv(denom) % M num * modinv(denom) num modinv(denom) modinv denom M n n r r print((pow(2, n, M) - comb(n, a) - comb(n, b) - 1) % M) print (pow(2, n, M) - comb(n, a) - comb(n, b) - 1) % M pow(2, n, M) - comb(n, a) - comb(n, b) - 1 pow(2, n, M) - comb(n, a) - comb(n, b) pow(2, n, M) - comb(n, a) pow(2, n, M) pow 2 n M comb(n, a) comb n a comb(n, b) comb n b 1 M a,b = map(int, input().split()) map(int, input().split()) a b = map(int, input().split()) map(int, input().split()) b def comb(n, r):
    num = denom = 1
    for i in range(1,r+1):
        num = (num*(n+1-i))%M
        denom = (denom*i)%M
    return num * modinv(denom) % M def comb(n, r):
    num = denom = 1
    for i in range(1,r+1):
        num = (num*(n+1-i))%M
        denom = (denom*i)%M
    return num * modinv(denom) % M comb M = 10**9 + 7 10**9 + 7 M def modinv(n):
    return pow(n, M-2, M) def modinv(n):
    return pow(n, M-2, M) modinv n,a,b = map(int, input().split()) map(int, input().split()) n
M = 10**9 + 7
n,a,b = map(int, input().split())

def modinv(n):
    return pow(n, M-2, M)

def comb(n, r):
    num = denom = 1
    for i in range(1,r+1):
        num = (num*(n+1-i))%M
        denom = (denom*i)%M
    return num * modinv(denom) % M

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