local mod = 1000000007
local mfl = math.floor

local function bmul(x, y)
  local x0, y0 = x % 31623, y % 31623
  local x1, y1 = mfl(x / 31623), mfl(y / 31623)
  return (x1 * y1 * 14122 + (x1 * y0 + x0 * y1) * 31623 + x0 * y0) % mod
end

local function badd(x, y)
  return (x + y) % mod
end

local function bsub(x, y)
  return x < y and x - y + mod or x - y
end

local function modpow(src, pow)
  local res = 1
  while 0 < pow do
    if pow % 2 == 1 then
      res = bmul(res, src)
      pow = pow - 1
    end
    src = bmul(src, src)
    pow = mfl(pow / 2)
  end
  return res
end

local function modinv(src)
  return modpow(src, mod - 2)
end

local fact = {1}
for i = 2, 300000 do
  fact[i] = bmul(i, fact[i - 1])
end

local function getComb(n, k)
  if k == 0 or k == n then return 1 end
  return bmul(fact[n], modinv(bmul(fact[k], fact[n - k])))
end

local ret = 0
local a, b, c = io.read("*n", "*n", "*n")
local n = a + b + c
for alen = 1, a do
  local remdigits = n - alen - 1
  local rema = a - alen
  local remb = b - 1
  -- 1 + 2 + 4 + ... + 2^(dig - 1)
  local mul = bsub(modpow(2, remdigits), 1)
  mul = bmul(mul, getComb(remdigits - 1, rema))
  mul = bmul(mul, getComb(remb + c - 1, c - 1))
  ret = badd(ret, mul)
end
print(ret)