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

mod = 10**9+7



def cmb2(n, r, mod):

    res = 1

    for k in range(1, r+1):

        res *= (n-k+1)*pow(k,(mod-2),mod)%mod

        res %= mod

    return res



def power(a, n, mod):

  bi=str(format(n,"b")) #2進数

  res=1

  for i in range(len(bi)):

    res=(res*res) %mod

    if bi[i]=="1":

      res=(res*a) %mod

  return res



ans = power(2, n, mod) - cmb2(n, a, mod) - cmb2(n, b, mod) -1

ans %= mod

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

mod = 10**9+7



def cmb2(n, r, mod):

    res = 1

    temp = 1

    for k in range(1, r+1):

        res *= (n-k+1)

        temp *= k

        res %= mod

        temp %= mod

    res *= pow(temp,(mod-2),mod)

    res %= mod

    return res



def power(a, n, mod):

    bi=str(format(n,"b")) #2進数

    res=1

    for i in range(len(bi)):

        res=(res*res) %mod

        if bi[i]=="1":

            res=(res*a) %mod

    return res



ans = power(2, n, mod) - cmb2(n, a, mod) - cmb2(n, b, mod) -1

ans %= mod

print(ans)

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


def cmb2(n, r, mod):
    res = 1
    for k in range(1, r + 1):
        res *= (n - k + 1) * pow(k, (mod - 2), mod) % mod
        res %= mod
    return res


def power(a, n, mod):
    bi = str(format(n, "b"))  # 2進数
    res = 1
    for i in range(len(bi)):
        res = (res * res) % mod
        if bi[i] == "1":
            res = (res * a) % mod
    return res


ans = power(2, n, mod) - cmb2(n, a, mod) - cmb2(n, b, mod) - 1
ans %= mod
print(ans)

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


def cmb2(n, r, mod):
    res = 1
    temp = 1
    for k in range(1, r + 1):
        res *= n - k + 1
        temp *= k
        res %= mod
        temp %= mod
    res *= pow(temp, (mod - 2), mod)
    res %= mod
    return res


def power(a, n, mod):
    bi = str(format(n, "b"))  # 2進数
    res = 1
    for i in range(len(bi)):
        res = (res * res) % mod
        if bi[i] == "1":
            res = (res * a) % mod
    return res


ans = power(2, n, mod) - cmb2(n, a, mod) - cmb2(n, b, mod) - 1
ans %= mod
print(ans)

+    temp = 1 -        res *= (n - k + 1) * pow(k, (mod - 2), mod) % mod +        res *= n - k + 1 +        temp *= k +        temp %= mod +    res *= pow(temp, (mod - 2), mod) +    res %= mod