local n, h, w = io.read("*n", "*n", "*n")

local function solve(n, x)
  n = 1LL * n
  x = 1LL * x
  if n % 2LL == 0LL then
    n = n / 2LL
    return n * n * (x - 1LL)
  else
    n = n / 2LL
    return n * (n + 1) * (x - 1LL)
  end
end

local r1 = solve(n, h)
local r2 = solve(n, w)
local ret = tostring(r1 + r2):gsub("LL", "")
print(ret)