def binom(n, r, mod):

    if n < r or n < 0 or r < 0: return 0

    

    if n - r < r: r = n - r

    if r == 0: return 1

    elif r == 1: return n



    numerator = [(n - r + 1 + k) % mod for k in range(r)]  # (n-r+1)*(n-r+2)*...*(n-1)*n

    denominator = [1 + k for k in range(r)]         # 1*2*...*(r-1)*r



    X = 1; Y = 1

    for k in range(r):

        X = (X * ((n - r + 1 + k) % mod)) % mod

        Y = (Y * ((1 + k) % mod)) % mod

    return X * pow(Y, mod-2, mod)



MOD = 10**9 + 7

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

ans = (pow(2, n, MOD) - 1 - ((binom(n, a, MOD) + binom(n, b, MOD)) % MOD)) % MOD

print(ans)
def binom(n, r, mod):

    if n < r or n < 0 or r < 0: return 0

    

    if n - r < r: r = n - r

    if r == 0: return 1

    elif r == 1: return n



    X = 1; Y = 1

    for k in range(r):

        X = (X * ((n - r + 1 + k) % mod)) % mod

        Y = (Y * ((1 + k) % mod)) % mod

    return X * pow(Y, mod-2, mod)



MOD = 10**9 + 7

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

ans = (pow(2, n, MOD) - 1 - ((binom(n, a, MOD) + binom(n, b, MOD)) % MOD)) % MOD

print(ans)
def binom(n, r, mod):
    if n < r or n < 0 or r < 0:
        return 0
    if n - r < r:
        r = n - r
    if r == 0:
        return 1
    elif r == 1:
        return n
    numerator = [(n - r + 1 + k) % mod for k in range(r)]  # (n-r+1)*(n-r+2)*...*(n-1)*n
    denominator = [1 + k for k in range(r)]  # 1*2*...*(r-1)*r
    X = 1
    Y = 1
    for k in range(r):
        X = (X * ((n - r + 1 + k) % mod)) % mod
        Y = (Y * ((1 + k) % mod)) % mod
    return X * pow(Y, mod - 2, mod)


MOD = 10**9 + 7
n, a, b = list(map(int, input().split()))
ans = (pow(2, n, MOD) - 1 - ((binom(n, a, MOD) + binom(n, b, MOD)) % MOD)) % MOD
print(ans)

def binom(n, r, mod):
    if n < r or n < 0 or r < 0:
        return 0
    if n - r < r:
        r = n - r
    if r == 0:
        return 1
    elif r == 1:
        return n
    X = 1
    Y = 1
    for k in range(r):
        X = (X * ((n - r + 1 + k) % mod)) % mod
        Y = (Y * ((1 + k) % mod)) % mod
    return X * pow(Y, mod - 2, mod)


MOD = 10**9 + 7
n, a, b = list(map(int, input().split()))
ans = (pow(2, n, MOD) - 1 - ((binom(n, a, MOD) + binom(n, b, MOD)) % MOD)) % MOD
print(ans)

-    numerator = [(n - r + 1 + k) % mod for k in range(r)]  # (n-r+1)*(n-r+2)*...*(n-1)*n -    denominator = [1 + k for k in range(r)]  # 1*2*...*(r-1)*r