k = 2 *10**5
mod = 10**9+7

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

modinv_table = [-1]*(k+1)
for i in range(1,k+1):
    modinv_table[i] = pow(i,-1,mod)

def binomial_coefficients(n,k):
    ans = 1
    for i in range(k):
        ans *= n-i
        ans *= modinv_table[i+1]
        ans %= mod
    return ans
print((pow(2,n,mod)-binomial_coefficients(n,a)-binomial_coefficients(n,b)-1)%mod) k = 2 *10**5 k 2 *10**5 2 10**5 10 5 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 modinv_table = [-1]*(k+1) modinv_table [-1]*(k+1) [-1] -1 k+1 k 1 for i in range(1,k+1):
    modinv_table[i] = pow(i,-1,mod) i range(1,k+1) range 1 k+1 k 1 modinv_table[i] = pow(i,-1,mod) modinv_table[i] modinv_table i pow(i,-1,mod) pow i -1 mod def binomial_coefficients(n,k):
    ans = 1
    for i in range(k):
        ans *= n-i
        ans *= modinv_table[i+1]
        ans %= mod
    return ans binomial_coefficients ans = 1 ans 1 for i in range(k):
        ans *= n-i
        ans *= modinv_table[i+1]
        ans %= mod
     i range(k) range k ans *= n-i ans n-i n i ans *= modinv_table[i+1] ans modinv_table[i+1] modinv_table i+1 i 1 ans %= mod ans mod return ans ans n n k k print((pow(2,n,mod)-binomial_coefficients(n,a)-binomial_coefficients(n,b)-1)%mod) print (pow(2,n,mod)-binomial_coefficients(n,a)-binomial_coefficients(n,b)-1)%mod pow(2,n,mod)-binomial_coefficients(n,a)-binomial_coefficients(n,b)-1 pow(2,n,mod)-binomial_coefficients(n,a)-binomial_coefficients(n,b) pow(2,n,mod)-binomial_coefficients(n,a) pow(2,n,mod) pow 2 n mod binomial_coefficients(n,a) binomial_coefficients n a binomial_coefficients(n,b) binomial_coefficients n b 1 mod k = 2 *10**5 2 *10**5 k def binomial_coefficients(n,k):
    ans = 1
    for i in range(k):
        ans *= n-i
        ans *= modinv_table[i+1]
        ans %= mod
    return ans def binomial_coefficients(n,k):
    ans = 1
    for i in range(k):
        ans *= n-i
        ans *= modinv_table[i+1]
        ans %= mod
    return ans binomial_coefficients modinv_table = [-1]*(k+1) [-1]*(k+1) modinv_table n, a, b = map(int,input().split()) map(int,input().split()) n a, b = map(int,input().split()) map(int,input().split()) a b = map(int,input().split()) map(int,input().split()) b mod = 10**9+7 10**9+7 mod
k = 2 *10**5
mod = 10**9+7

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

modinv_table = [-1]*(k+1)
for i in range(1,k+1):
    modinv_table[i] = pow(i,-1,mod)

def binomial_coefficients(n,k):
    ans = 1
    for i in range(k):
        ans *= n-i
        ans *= modinv_table[i+1]
        ans %= mod
    return ans
print((pow(2,n,mod)-binomial_coefficients(n,a)-binomial_coefficients(n,b)-1)%mod)