SIZE=3*10**5+1; MOD=10**9+7 #998244353 #ここを変更する

inv = [0]*SIZE  # inv[j] = j^{-1} mod MOD
fac = [0]*SIZE  # fac[j] = j! mod MOD
finv = [0]*SIZE # finv[j] = (j!)^{-1} mod MOD
fac[0] = fac[1] = 1
finv[0] = finv[1] = 1
for i in range(2,SIZE):
    fac[i] = fac[i-1]*i%MOD
finv[-1] = pow(fac[-1],MOD-2,MOD)
for i in range(SIZE-1,0,-1):
    finv[i-1] = finv[i]*i%MOD
    inv[i] = finv[i]*fac[i-1]%MOD

def choose(n,r): # nCk mod MOD の計算
    if 0 <= r <= n:
        return (fac[n]*finv[r]%MOD)*finv[n-r]%MOD
    else:
        return 0

a,b,c = map(int,input().split())
n = a+b+c
r = 0
p = 1
for i in range(1,a+1):
    r += choose(n-i-1-1,c-1)*choose(a+b-i-1,b-1)%MOD

ans = 0
for i in range(n):
    ans += r*p%MOD
    if n-1-i-1 <= a:
        j = n-1-i-1
        r -= choose(n-j-1-1,c-1)*choose(a+b-j-1,b-1)
        r %= MOD
    if r==0: break
    p = p*2%MOD
print(ans%MOD)