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

M = 10 ** 9 + 7

all = pow(2, n, M) - 1
all %= M

def C(n,x):
    num = 1
    den = 1
    for i in range(x):
        num *= (n-i)
        num %= M
        den *= (i+1)
        den %= M

    inv = pow(den, M-2, M)

    return num * inv % M

ans = all - C(n,a) - C(n,b)
ans %= M
print(ans) n, a, b = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split a b M = 10 ** 9 + 7 M 10 ** 9 + 7 10 ** 9 10 9 7 all = pow(2, n, M) - 1 all pow(2, n, M) - 1 pow(2, n, M) pow 2 n M 1 all %= M all M def C(n,x):
    num = 1
    den = 1
    for i in range(x):
        num *= (n-i)
        num %= M
        den *= (i+1)
        den %= M

    inv = pow(den, M-2, M)

    return num * inv % M C num = 1 num 1 den = 1 den 1 for i in range(x):
        num *= (n-i)
        num %= M
        den *= (i+1)
        den %= M

     i range(x) range x num *= (n-i) num n-i n i num %= M num M den *= (i+1) den i+1 i 1 den %= M den M inv = pow(den, M-2, M) inv pow(den, M-2, M) pow den M-2 M 2 M return num * inv % M num * inv % M num * inv num inv M n n x x ans = all - C(n,a) - C(n,b) ans all - C(n,a) - C(n,b) all - C(n,a) all C(n,a) C n a C(n,b) C n b ans %= M ans M print(ans) print ans b = map(int, input().split()) map(int, input().split()) b n, a, b = map(int, input().split()) map(int, input().split()) n all %= M M all ans = all - C(n,a) - C(n,b) all - C(n,a) - C(n,b) ans a, b = map(int, input().split()) map(int, input().split()) a def C(n,x):
    num = 1
    den = 1
    for i in range(x):
        num *= (n-i)
        num %= M
        den *= (i+1)
        den %= M

    inv = pow(den, M-2, M)

    return num * inv % M def C(n,x):
    num = 1
    den = 1
    for i in range(x):
        num *= (n-i)
        num %= M
        den *= (i+1)
        den %= M

    inv = pow(den, M-2, M)

    return num * inv % M C all = pow(2, n, M) - 1 pow(2, n, M) - 1 all ans %= M M ans M = 10 ** 9 + 7 10 ** 9 + 7 M
n, a, b = map(int, input().split())

M = 10 ** 9 + 7

all = pow(2, n, M) - 1
all %= M

def C(n,x):
    num = 1
    den = 1
    for i in range(x):
        num *= (n-i)
        num %= M
        den *= (i+1)
        den %= M

    inv = pow(den, M-2, M)

    return num * inv % M

ans = all - C(n,a) - C(n,b)
ans %= M
print(ans)