#!/usr/bin/env python2 


class El():
    def __init__(self, val=None, nxt=None):
        self.val = val
        self.nxt = nxt

    def getNext(self):
        return self.nxt

    def getVal(self):
        return self.val


class Ll():
    def __init__(self, first):
        self.first = first

    def iterv(self):
        el = self.first
        while True:
            yield el.getVal()
            el = el.getNext()
            if not el: break

a = Ll(El("first", El("second")))

for i in a.iterv():
    print i