import sys
from collections import defaultdict as DD
from itertools import combinations as comb

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

for k, v in D.items():
    for i in v:
        w = v - {i}
        if all(b in D[a] for a,b in comb(w,2)):
            print(",".join(sorted({k}|w)))
            #sys.exit(0)