N = int(input())
dic = {}
for i in range(0, N):
    S = input()
    dic[len(S)] = dic.get(len(S), 0) + 1
max = 0
ans = 0
for x, y in dic.items():
    if y > max or y == max and x > ans:
        max = y
        ans = x
print(ans-2)