import sys
from collections import defaultdict as DD

D = DD(set)
S = set()
for i in sys.stdin.read().strip().split('\n'):
    a, b = i.split("-")
    D[a].add(b)
    D[b].add(a)
    S.add(a)
    S.add(b)

G = set()
m = 0
def grow(group:set[str], l:int):
    global m
    key = ','.join(sorted(group))
    if key in G:
        return
    G.add(key)
    if l>m:
        print(l, key)
        m = l
    rest = S - group
    for r in rest:
        if len(group & D[r]) == l:
            ng = group.copy()
            ng.add(r)
            yield (l+1, ng)
            yield from grow(ng, l+1)

for a, B in D.items():
    for b in B:
        for i,s in grow({a,b},2):
            pass