from os import popen
import sys
def mkset(target):
cmd = "grep -il " + target + " *"
return set(popen(cmd))
args = sys.argv
args = args[1:]
if len(args) == 0: exit(0)
res = mkset(args[0])
for s in args[1:]:
res = res.intersection(mkset(s))
res = list(res)
res.sort()
for f in res:
print(f[:-1])