MOD = 10**9 + 7
n, a, b = map(int, input().split())

def comb(n, k):
    x, y = 1, 1
    for i in range(n, n-k, -1):
        x = x * i % MOD
    for i in range(1, k+1):
        y = y * i % MOD
    return x*pow(y, MOD-2, MOD) % MOD

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

def comb(n, k):
    x, y = 1, 1
    for i in range(n, n-k, -1):
        x = x * i % MOD
    for i in range(1, k+1):
        y = y * i % MOD
    return x*pow(y, MOD-2, MOD) % MOD

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

print(ans)