import sys

def find_transformations(input_word, output_word, graph):
    seen = set([input_word])
    queue = [(input_word, ())]
    while queue:
        (i, parents) = queue.pop(0)
        can_make = [j for j in graph[i] if j not in seen]
        if output_word in can_make:
            print ' '.join(parents), output_word
            return True
        new_parents = parents + (i,)
        queue.extend([(w, new_parents) for w in can_make])
        for w in can_make: seen.add(w)
    return False

if __name__ == '__main__':
    assert len(sys.argv[1]) == len(sys.argv[2])
    graph = __import__('graph_%d' % len(sys.argv[1])).graph
    find_transformations(sys.argv[1], sys.argv[2], graph)