"""

"""

import sys
from sys import stdin

N = int(stdin.readline())

S = []

for i in range(N):

    s = stdin.readline()[:-1]

    for i in range(len(s)-1):
        if s[i] > s[i+1]:
            break
    else:
        S.append(s)

S.sort()

dp = [0] * 26

for i in S:
    dp[ord(i[-1])-ord('a')] = max( dp[ord(i[-1])-ord('a')],max(dp[:ord(i[0])-ord('a')+1]) + len(i))

#print (dp)
print (max(dp))