import sys sys.setrecursionlimit(10**6) int1 = lambda x: int(x)-1 p2D = lambda x: print(*x, sep="\n") def II(): return int(sys.stdin.buffer.readline()) def FI(): return float(sys.stdin.buffer.readline()) def MI(): return map(int, sys.stdin.buffer.readline().split()) def MF(): return map(float, sys.stdin.buffer.readline().split()) def MI1(): return map(int1, sys.stdin.buffer.readline().split()) def LI(): return list(map(int, sys.stdin.buffer.readline().split())) def LI1(): return list(map(int1, sys.stdin.buffer.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def BI(): return sys.stdin.buffer.readline().rstrip() def SI(): return sys.stdin.buffer.readline().rstrip().decode() dij = [(0, 1), (-1, 0), (0, -1), (1, 0)] inf = 10**16 # md = 998244353 md = 10**9+7 def nHr(hn, hr): return nCr(hn+hr-1, hr-1) def nPr(com_n, com_r): if com_n < com_r: return 0 return fac[com_n]*ifac[com_n-com_r]%md def nCr(com_n, com_r): if com_r < 0: return 0 if com_n < com_r: return 0 return fac[com_n]*ifac[com_r]%md*ifac[com_n-com_r]%md # 準備 n_max = 300005 fac = [1] for i in range(1, n_max+1): fac.append(fac[-1]*i%md) ifac = [1]*(n_max+1) ifac[n_max] = pow(fac[n_max], md-2, md) for i in range(n_max-1, 1, -1): ifac[i] = ifac[i+1]*(i+1)%md a,b,c=MI() n=a+b+c pw=[1] for _ in range(n):pw.append(pw[-1]*2%md) ans=0 ab=0 for l in range(2,a+b+1): r=n-1-l ab=(ab+nCr(a+b-l,b-1))%md way=nCr(r,c-1)*ab%md ev=((c-1)*(pw[r]-1)*pow(r,md-2,md)+pw[r])%md ans=(ans+way*ev%md)%md # print(ab,way,ev,ans) print(ans)