import sys
import io, os
input = sys.stdin.readline

n = int(input())
S = [input().rstrip() for i in range(n)]
X = [0]*26
T = []
for s in S:
    temp = []
    for c in s:
        temp.append(ord(c)-ord('a'))
    if sorted(temp) != temp:
        continue
    T.append((temp[0], temp[-1], len(s)))
if not T:
    print(0)
    exit()
T.sort()
for p, q, l in T:
    X[q] = max(X[q], max(X[0:p+1])+l)
print(max(X))