from collections import defaultdict, deque
from itertools import groupby, permutations
from sys import stdin

edges = defaultdict(list)
for line in stdin.read().strip().split():
    for key, value in permutations(line.split('-')):
        if key != 'end' and value != 'start': edges[key].append(value)
paths = set()
queue = deque([('start',)])
while queue:
    if (head := queue.popleft()) in paths: continue
    paths.add(head)
    if (chin := head[-1]) == 'end': continue
    for neck in edges[chin]:
        top = head + (neck,)
        if sum(len(tuple(group)) - 1 for cave, group in groupby(sorted(top))
               if cave.islower()) > 1: continue
        queue.append(top)
print(sum(path[-1] == 'end' for path in paths))