-- your code goes here
local error1 = "100,1"
local error2 = "100.1"
local error3 = "100A"
local error4 = "100,1B"
local error5 = "100.1C"
local success1 = "100"
local success2 = "+100"
local success3 = "-100"

function isValidNumber(number)
	return string.find(number, "^[+-]?%d+$") and true or false
end


print(tostring(isValidNumber(error1)))
print(tostring(isValidNumber(error2)))
print(tostring(isValidNumber(error3)))
print(tostring(isValidNumber(error4)))
print(tostring(isValidNumber(error5)))
print(tostring(isValidNumber(success1)))
print(tostring(isValidNumber(success2)))
print(tostring(isValidNumber(success3)))