def my_pow(a, n, r=1):
    r = ((r * a) % 1000000007) if n & 0b1 else r
    if n > 2:
        return my_pow((a * a) % 1000000007, n // 2, r)
    else:
        return r


def my_div(a, b):
    return (a * my_pow(b, 1000000005)) % 1000000007


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

my_fact = [-1, 1, 1]
tmp = 1
for i in range(2, 300000):
    my_fact.append(my_fact[-1] * i % 1000000007)

my_2xp = [1]
tmp = 1
for i in range(1, 299999):
    my_2xp.append(my_2xp[-1] * 2 % 1000000007)

res = 0
k = a + b + c - 1
for i in range(0, a):
    k -= 1
    tmp = my_2xp[k] - 1
    tmp = (tmp * my_fact[k]) % 1000000007
    res += my_div(tmp, my_fact[a - i])
    res %= 1000000007

res = my_div(res, (my_fact[b] * my_fact[c]) % 1000000007)
print(res)