from operator import itemgetter
import sys
input = lambda: sys.stdin.readline().rstrip()
#INF = 10**18

N = int(input())
l = []
total = 0
for i in range(N):
    S = input()
    for i in range(len(S)-1):
        if S[i] > S[i+1]:
            break
    else:
        l.append([S[0],S[-1],-len(S),S])
        total += len(S)
l.sort(key=itemgetter(0,1,2))

dp = [[0]*(total+1) for i in range(len(l)+1)]

last = "a"
for i in range(len(l)):
    flag = False
    for j in range(total):
        if l[i][0] >= last:
            dp[i+1][j+1] = max(dp[i][j] - l[i][2], dp[i+1][j])
            flag = True
        else:
            dp[i+1][j+1] = max(dp[i+1][j], dp[i][j+1])
    if flag:
        last = l[i][1]

print(dp[len(l)][total])