n, m = map(int, input().split())
d = {}
st = set()
for i in range(n):
s = input()
if len(s) < m:
continue
st.add(s)
try:
d[s] += 1
except:
d[s] = 1
l = list(st)
l.sort(key=lambda t: (-d[t], -len(t), t))
print(*l, sep="\n")