pythondef solve(N, rules):
ret = 0
for subset in range(2 ** N):
danger = []
for rs in rules:
hit = 0
for r in rs:
if subset & (1 << (r - 1)):
hit += 1
else:
d = r
if hit == 3:
danger = []
break
if hit == 2:
danger.append(d)
ret = max(ret, len(set(danger)))
return ret