import sys
import networkx as nx
input = [line.strip().split("-") for line in sys.stdin]
nodes = set([node for pair in input for node in pair])
k_nodes = [node for node in nodes if node.startswith("t")]
G = nx.Graph()
G.add_nodes_from(nodes)
G.add_edges_from(input)
cliques = list(nx.enumerate_all_cliques(G))
part1 = 0
for clique in cliques:
if len(clique) < 3:
continue
elif len(clique) > 3:
break
elif any(node in k_nodes for node in clique):
part1 += 1
print(part1)
part2 = ",".join(sorted(cliques[-1]))
print(part2)