def rec(a):
    print "rec: starting, a is:",a
    a = a - 1

    if(a > 0):
        print "rec: calling rec again,a:",a
        rec(a)
        print "rec:return from rec, a is:",a
    else:
        print "all done!, a is",a
        return


def getANumber(prompt):
    userInput = raw_input(prompt)
    try:
        retVal = int(userInput)
        return(retVal)
    except:
        print "Not a valid integer, try again"
        retVal = getANumber(prompt)
        return(retVal)