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

mod = 10 ** 9 + 7
n = 5*10**5+5
fact = [1] * (n + 1)
invfact = [1] * (n + 1)
for i in range(1, n):
    fact[i + 1] = ((i+1) * fact[i]) % mod
invfact[n] = pow(fact[n], mod - 2, mod)
for i in range(n - 1, -1, -1):
    invfact[i] = invfact[i + 1] * (i + 1) % mod

def comb(n, r):
    if n < 0 or r < 0 or n - r < 0:
        return 0
    return fact[n] * invfact[r] * invfact[n - r] % mod

N = a + b + c
ans = 0
for i in range(1, N - 1):
    na = a - (N - i - 1)
    nb = b - 1
    if na < 0:
        continue
    ans += comb(na + nb + c, na) * comb(nb + c, nb) * c * (pow(2, i, mod) - 1) * pow(i, mod - 2, mod)
    ans %= mod

print(ans)