n = int(input())
S = []
for _ in range(n):
    s = input()
    if s == "".join(sorted(s)):
        S.append(s)
S.sort()
A = [0]*125
for s in S:
    r = ord(s[-1])
    A[r] = max(A[r],max(A[:ord(s[0])+1])+len(s))
print(max(A))