#!/usr/bin/env python3
import sys
import re
from collections import defaultdict

E = defaultdict(list)


# Parse in edges
for l in sys.stdin:
    a, b = l.strip().split('-')
    E[a].append(b)
    E[b].append(a)

smallre = re.compile('[a-z]+')
def issmall(n):
    return smallre.match(n)

paths = 0
def search(n, path):
    global paths
    if n == 'end':
        paths += 1
        return
    if issmall(n) and n in path:
        return
    for c in E[n]:
        search(c, path + n)

search("start", "")

print(paths)