import sys
readline = sys.stdin.readline
mod = 10**9+7
def frac(limit):
    frac = [1]*limit
    for i in range(2,limit):
        frac[i] = i * frac[i-1]%mod
    fraci = [None]*limit
    fraci[-1] = pow(frac[-1], mod -2, mod)
    for i in range(-2, -limit-1, -1):
        fraci[i] = fraci[i+1] * (limit + i + 1) % mod
    return frac, fraci
frac, fraci = frac(1341398)
def comb(a, b):
    if not a >= b >= 0:
        return 0
    return frac[a]*fraci[b]*fraci[a-b]%mod

X, Y, Z = map(int, readline().split())
M = X+Y+Z+1

C = [0] + [(-1)**(M-k+1)*pow(2, k-1, mod)*comb(M, k)%mod for k in range(1, M+1)]
if M & 1:
    C[0] = 1
for i in range(1, M+1):
    C[i] = (C[i] + C[i-1]) % mod
ans = 0
for j in range(1, M):
    ans = (ans + C[j]*pow(pow(2, j, mod), mod-2, mod)*comb(X+j-1, X)*comb(Y+j-1, Y)*comb(Z+j-1, Z)) % mod
if M == 1:
    ans = 1
print(ans%mod)