n = int(input())
eye_dic = {}
max_eye = 0
max_count = 0
for i in range(n):
    eye=len(input())
    eye_dic[eye]=eye_dic.get(eye,0)+1
for eye,count in eye_dic.items():
    if count>max_count or count==max_count and eye>max_eye:
        max_count = count
        max_eye = eye
print(max_eye-2)