#Ceri Puddle p150771
print ("Hello")

num = 0
total = 0

while (num != -1):
    num = int(input("Enter Number (-1 to exit) :"))
    if (num <= -2):
     print ("You can not enter negitive number")
    else:
     total = num + total

else:
        print("Your total is {}".format(total))
        print("Goodbye!")