calculate

args = {...}
if #args ~= 2 then
args = {...}
firstArg = args[1]
symbol = args[2]
secondArg = args[3]
else
args = {...}
lastAnswer = fs.open("Ans","r")
firstArg = lastAnswer.readAll()
symbol = args[1]
secondArg = args[2]
lastAnswer.close()
end
if symbol == "+" then
 output = firstArg+secondArg
elseif symbol == "-" then
 output = firstArg-secondArg
elseif symbol == "/" then
 output = firstArg/secondArg
elseif symbol == "*" then
 output = firstArg*secondArg
end
print(output)
lastAnswer = fs.open("Ans","w")
lastAnswer.write(output)
lastAnswer.close()