def nCr(n, r):

    mod=10**9+7

    r = min(r, n-r)

    numer = denom = 1

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

        numer = numer * (n+1-i) % mod

        denom = denom * i % mod

    return numer * pow(denom, mod-2, mod) % mod

   

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

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

ans=s-1-nCr(n,a)-nCr(n,b)

while ans<0:

   ans+=10**9+7

print(ans)
mod=10**9+7

def nCr(n, r):

    r = min(r, n-r)

    numer = denom = 1

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

        numer = numer * (n+1-i) % mod

        denom = denom * i % mod

    return numer * pow(denom, mod-2, mod) % mod

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

f=pow(2, n, mod)-1-nCr(n,a)-nCr(n,b)



while f<0:

    f+=mod

print(f)
def nCr(n, r):
    mod = 10**9 + 7
    r = min(r, n - r)
    numer = denom = 1
    for i in range(1, r + 1):
        numer = numer * (n + 1 - i) % mod
        denom = denom * i % mod
    return numer * pow(denom, mod - 2, mod) % mod


n, a, b = list(map(int, input().split()))
s = pow(2, n, 10**9 + 7)
ans = s - 1 - nCr(n, a) - nCr(n, b)
while ans < 0:
    ans += 10**9 + 7
print(ans)

mod = 10**9 + 7


def nCr(n, r):
    r = min(r, n - r)
    numer = denom = 1
    for i in range(1, r + 1):
        numer = numer * (n + 1 - i) % mod
        denom = denom * i % mod
    return numer * pow(denom, mod - 2, mod) % mod


n, a, b = list(map(int, input().split()))
f = pow(2, n, mod) - 1 - nCr(n, a) - nCr(n, b)
while f < 0:
    f += mod
print(f)

+mod = 10**9 + 7 + + -    mod = 10**9 + 7 -s = pow(2, n, 10**9 + 7) -ans = s - 1 - nCr(n, a) - nCr(n, b) -while ans < 0: -    ans += 10**9 + 7 -print(ans) +f = pow(2, n, mod) - 1 - nCr(n, a) - nCr(n, b) +while f < 0: +    f += mod +print(f)