print("Hello!")
num1=int(input("Enter Number (-1 To Exit) :"))
if(num1>-1):
    num2=int(input("Enter Number (-1 To Exit) :"))
    if(num2>-1):
        num3=int(input("Enter Number (-1 To Exit) :"))
        if(num3>-1):
            num4=int(input("Enter Number (-1 To Exit) :"))
            total=num1+num2+num3+num4
            print("Your Total Is : {0}".format(total))
else:
    print("Goodbye!")