import sys

inp = {}
solutions = []

def juzgfvzgv(poi, path, twice):
    nex = inp[poi]
    #print(nex)
    for i in nex:
        if i == 'end':
            solutions.append(path + [i])
            continue
        elif i.islower() and i in path:
            if twice and i != 'start':
                juzgfvzgv(i, path + [i], False)
            else:
                continue
        else:
            juzgfvzgv(i, path + [i], twice)

with open(sys.argv[1], 'r') as f:
    for i in f.readlines():
        i = i.strip()
        temp1, temp2 = i.split('-', 1)
        inp.setdefault(temp1, list()).append(temp2)
        inp.setdefault(temp2, list()).append(temp1)

juzgfvzgv('start', ['start'], True)
for i in solutions:
    print(i)
print(len(solutions))