calc

local input = {...}
local num1 = input[1]
local num2 = input[2]
local op = input[3]
local cop = false

if op == "+" or op == "-" or op == "*" or op == "/" then
  cop = true
end

if tonumber(num1) == nil or tonumber(num2) == nil or cop == false or input[4] ~= null then
  print("Usage: calc %number1% %number2% %operator(+,-,*,/)%")
elseif num2 == "0" and op == "/" then
  print("Can't devide by 0")
else
  write("Result: ")
  if op == "+" then
    print(num1 + num2)
  elseif op == "-" then
    print(num1 - num2)
  elseif op == "*" then
    print(num1 * num2)
  else
    print(num1 / num2)
  end
end