N = int(raw_input())
eyes = []
for i in range(0, 999):
	eyes.append(0)
for i in range(0, N):
	s = raw_input()
	eyes[len(s)-2] += 1
max = 0
tmp = -1
for i in range(0, 999):
	if max <= eyes[i]:
		tmp = i
		max = eyes[i]
print tmp