mod = 10**9+7

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

def comb(n, r):
    c = 1
    for i in range(r):
        c *= n-i
        c %= mod

    d = 1
    for i in range(1, r+1):
        d *= i
        d %= mod

    return (c * pow(d, mod-2, mod)) % mod

ans = pow(2, n, mod) - 1 - comb(n, a) - comb(n, b)

ans %= mod

print(ans)
 mod = 10**9+7 mod 10**9+7 10**9 10 9 7 n, a, b = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split a b def comb(n, r):
    c = 1
    for i in range(r):
        c *= n-i
        c %= mod

    d = 1
    for i in range(1, r+1):
        d *= i
        d %= mod

    return (c * pow(d, mod-2, mod)) % mod comb c = 1 c 1 for i in range(r):
        c *= n-i
        c %= mod

     i range(r) range r c *= n-i c n-i n i c %= mod c mod d = 1 d 1 for i in range(1, r+1):
        d *= i
        d %= mod

     i range(1, r+1) range 1 r+1 r 1 d *= i d i d %= mod d mod return (c * pow(d, mod-2, mod)) % mod (c * pow(d, mod-2, mod)) % mod c * pow(d, mod-2, mod) c pow(d, mod-2, mod) pow d mod-2 mod 2 mod mod n n r r ans = pow(2, n, mod) - 1 - comb(n, a) - comb(n, b) ans pow(2, n, mod) - 1 - comb(n, a) - comb(n, b) pow(2, n, mod) - 1 - comb(n, a) pow(2, n, mod) - 1 pow(2, n, mod) pow 2 n mod 1 comb(n, a) comb n a comb(n, b) comb n b ans %= mod ans mod print(ans) print ans a, b = map(int, input().split()) map(int, input().split()) a ans = pow(2, n, mod) - 1 - comb(n, a) - comb(n, b) pow(2, n, mod) - 1 - comb(n, a) - comb(n, b) ans ans %= mod mod ans mod = 10**9+7 10**9+7 mod def comb(n, r):
    c = 1
    for i in range(r):
        c *= n-i
        c %= mod

    d = 1
    for i in range(1, r+1):
        d *= i
        d %= mod

    return (c * pow(d, mod-2, mod)) % mod def comb(n, r):
    c = 1
    for i in range(r):
        c *= n-i
        c %= mod

    d = 1
    for i in range(1, r+1):
        d *= i
        d %= mod

    return (c * pow(d, mod-2, mod)) % mod comb n, a, b = map(int, input().split()) map(int, input().split()) n b = map(int, input().split()) map(int, input().split()) b
mod = 10**9+7

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

def comb(n, r):
    c = 1
    for i in range(r):
        c *= n-i
        c %= mod

    d = 1
    for i in range(1, r+1):
        d *= i
        d %= mod

    return (c * pow(d, mod-2, mod)) % mod

ans = pow(2, n, mod) - 1 - comb(n, a) - comb(n, b)

ans %= mod

print(ans)

