a,b,c=map(int,input().split())
mod=10**9+7

FACT=[1]
for i in range(1,2*10**5+1):
    FACT.append(FACT[-1]*i%mod)

FACT_INV=[pow(FACT[-1],mod-2,mod)]
for i in range(2*10**5,0,-1):
    FACT_INV.append(FACT_INV[-1]*i%mod)

FACT_INV.reverse()

def Combi(a,b):
    if 0<=b<=a:
        return FACT[a]*FACT_INV[b]*FACT_INV[a-b]%mod
    else:
        return 0

S=a+b+c
ANS=(1<<(S-3))*Combi(S-3,a-1)*Combi(S-3-(a-1),b-1)%mod


for i in range(S-3):
    COM=Combi(S-2,a-1)
    if S-(i+1)<=a:
        COM-=Combi(i,a-(S-(i+1)))

    ANS=(ANS+(1<<i)*COM*Combi(S-3-(a-1),b-1))%mod

print(ANS)