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

mod = 1000000007

def pow(x, n):
    ret = 1
    while n > 0:
        if (n & 1) == 1:
            ret = (ret * x) % mod
        x = (x * x) % mod
        n //= 2
    return ret

def inv(x):
    return pow(x, mod - 2)

def cmb(n, k):
    ret = 1
    for i in range(k):
        ret = (ret * (n - i) * inv(i + 1)) % mod
    return ret

print((pow(2, n) - cmb(n, a) - cmb(n, b) - 1) % mod) n, a, b = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split a b mod = 1000000007 mod 1000000007 def pow(x, n):
    ret = 1
    while n > 0:
        if (n & 1) == 1:
            ret = (ret * x) % mod
        x = (x * x) % mod
        n //= 2
    return ret pow ret = 1 ret 1 while n > 0:
        if (n & 1) == 1:
            ret = (ret * x) % mod
        x = (x * x) % mod
        n //= 2
     n > 0 n 0 if (n & 1) == 1:
            ret = (ret * x) % mod
         (n & 1) == 1 n & 1 n 1 1 ret = (ret * x) % mod ret (ret * x) % mod ret * x ret x mod x = (x * x) % mod x (x * x) % mod x * x x x mod n //= 2 n 2 return ret ret x x n n def inv(x):
    return pow(x, mod - 2) inv return pow(x, mod - 2) pow(x, mod - 2) pow x mod - 2 mod 2 x x def cmb(n, k):
    ret = 1
    for i in range(k):
        ret = (ret * (n - i) * inv(i + 1)) % mod
    return ret cmb ret = 1 ret 1 for i in range(k):
        ret = (ret * (n - i) * inv(i + 1)) % mod
     i range(k) range k ret = (ret * (n - i) * inv(i + 1)) % mod ret (ret * (n - i) * inv(i + 1)) % mod ret * (n - i) * inv(i + 1) ret * (n - i) ret n - i n i inv(i + 1) inv i + 1 i 1 mod return ret ret n n k k print((pow(2, n) - cmb(n, a) - cmb(n, b) - 1) % mod) print (pow(2, n) - cmb(n, a) - cmb(n, b) - 1) % mod pow(2, n) - cmb(n, a) - cmb(n, b) - 1 pow(2, n) - cmb(n, a) - cmb(n, b) pow(2, n) - cmb(n, a) pow(2, n) pow 2 n cmb(n, a) cmb n a cmb(n, b) cmb n b 1 mod def cmb(n, k):
    ret = 1
    for i in range(k):
        ret = (ret * (n - i) * inv(i + 1)) % mod
    return ret def cmb(n, k):
    ret = 1
    for i in range(k):
        ret = (ret * (n - i) * inv(i + 1)) % mod
    return ret cmb mod = 1000000007 1000000007 mod b = map(int, input().split()) map(int, input().split()) b def pow(x, n):
    ret = 1
    while n > 0:
        if (n & 1) == 1:
            ret = (ret * x) % mod
        x = (x * x) % mod
        n //= 2
    return ret def pow(x, n):
    ret = 1
    while n > 0:
        if (n & 1) == 1:
            ret = (ret * x) % mod
        x = (x * x) % mod
        n //= 2
    return ret pow def inv(x):
    return pow(x, mod - 2) def inv(x):
    return pow(x, mod - 2) inv n, a, b = map(int, input().split()) map(int, input().split()) n a, b = map(int, input().split()) map(int, input().split()) a
n, a, b = map(int, input().split())

mod = 1000000007

def pow(x, n):
    ret = 1
    while n > 0:
        if (n & 1) == 1:
            ret = (ret * x) % mod
        x = (x * x) % mod
        n //= 2
    return ret

def inv(x):
    return pow(x, mod - 2)

def cmb(n, k):
    ret = 1
    for i in range(k):
        ret = (ret * (n - i) * inv(i + 1)) % mod
    return ret

print((pow(2, n) - cmb(n, a) - cmb(n, b) - 1) % mod)
