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

MOD = 10**9 + 7
N = pow(2,n,MOD)

def com(n,r):
    s = 1
    for i in range(n-r+1, n+1):
        s *= i
        s %= MOD

    t = 1
    for j in range(1,r+1):
        t *= j
        t %= MOD


    return s * pow(t,MOD-2, MOD) % MOD

print((N - com(n, a) - com(n, b) - 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 N = pow(2,n,MOD) N pow(2,n,MOD) pow 2 n MOD def com(n,r):
    s = 1
    for i in range(n-r+1, n+1):
        s *= i
        s %= MOD

    t = 1
    for j in range(1,r+1):
        t *= j
        t %= MOD


    return s * pow(t,MOD-2, MOD) % MOD com s = 1 s 1 for i in range(n-r+1, n+1):
        s *= i
        s %= MOD

     i range(n-r+1, n+1) range n-r+1 n-r n r 1 n+1 n 1 s *= i s i s %= MOD s MOD t = 1 t 1 for j in range(1,r+1):
        t *= j
        t %= MOD


     j range(1,r+1) range 1 r+1 r 1 t *= j t j t %= MOD t MOD return s * pow(t,MOD-2, MOD) % MOD s * pow(t,MOD-2, MOD) % MOD s * pow(t,MOD-2, MOD) s pow(t,MOD-2, MOD) pow t MOD-2 MOD 2 MOD MOD n n r r print((N - com(n, a) - com(n, b) - 1) % (MOD)) print (N - com(n, a) - com(n, b) - 1) % (MOD) N - com(n, a) - com(n, b) - 1 N - com(n, a) - com(n, b) N - com(n, a) N com(n, a) com n a com(n, b) com n b 1 MOD MOD = 10**9 + 7 10**9 + 7 MOD n, a, b = map(int, input().split()) map(int, input().split()) n def com(n,r):
    s = 1
    for i in range(n-r+1, n+1):
        s *= i
        s %= MOD

    t = 1
    for j in range(1,r+1):
        t *= j
        t %= MOD


    return s * pow(t,MOD-2, MOD) % MOD def com(n,r):
    s = 1
    for i in range(n-r+1, n+1):
        s *= i
        s %= MOD

    t = 1
    for j in range(1,r+1):
        t *= j
        t %= MOD


    return s * pow(t,MOD-2, MOD) % MOD com b = map(int, input().split()) map(int, input().split()) b N = pow(2,n,MOD) pow(2,n,MOD) N a, b = map(int, input().split()) map(int, input().split()) a
n, a, b = map(int, input().split())

MOD = 10**9 + 7
N = pow(2,n,MOD)

def com(n,r):
    s = 1
    for i in range(n-r+1, n+1):
        s *= i
        s %= MOD

    t = 1
    for j in range(1,r+1):
        t *= j
        t %= MOD


    return s * pow(t,MOD-2, MOD) % MOD

print((N - com(n, a) - com(n, b) - 1) % (MOD))