n = int(input())
dict = {i:0 for i in range(0, 999)}
for i in range(n):
    si = input()
    dict[len(si) - 2] += 1
mode = -1
frequency = 0
for i in range(len(dict)):
    if dict[i] >= frequency:
        frequency = dict[i]
        mode = i
print(mode)