# 二分乗数法
def my_dif(a, b, m):
    # a-b
    tmp = a - b
    return tmp if tmp > 0 else tmp + m


def my_pow(a, n, m, r=1):
    # [a, n, m, r] = [底, 指数, 返値の最大値, 初項]
    a %= m
    if n % 2 == 1:
        r *= a
        r %= m
    if n <= 1:
        return r
    a *= a
    a %= m
    return my_pow(a, int(n / 2), m, r)


def my_mul(a, b, m):
    # a*b
    return ((a % m) * (b % m)) % m


def my_div(a, b, m):
    # a/b
    return my_mul(a, my_pow(b, m - 2, m), m)


# 入力の分解
output_max = 1000000000 + 7
s = input()
s = s.split()
inp = [int(tmp) for tmp in s]

a = inp[0]
b = inp[1]
c = inp[2]

# 階乗のチートシート作成
my_fact = [1, 1]
tmp = 1
for i in range(2, 300000):
    tmp *= i
    tmp %= output_max
    my_fact.append(tmp)

# 2のべき乗のチートシート作成
my_2xp = [1]
tmp = 1
for i in range(1, 300000):
    tmp *= 2
    tmp %= output_max
    my_2xp.append(tmp)

res = 0
for i in range(2, a+2):
    k = a + b + c - i
    # tmp = 1
    # tmp = ((tmp << k) - 1) % output_max
    tmp = my_2xp[k] - 1
    tmp = (tmp * my_fact[k - 1]) % output_max
    res += my_div(tmp, my_fact[a - i + 1], output_max)
    res %= output_max

res = my_div(res, (my_fact[b - 1] * my_fact[c - 1]) % output_max, output_max)
print(res)