N = int(input())
S = [input() for _ in range(N)]

S.sort()

dp = {}
for c in 'abcdefghijklmnopqrstuvwxyz':
    dp[c] = -1
dp[chr(ord('a')-1)]=0

for l in S:
    #print("*", l)
    if ''.join(sorted(l)) != l:
        continue
    lc = l[-1]
    for c in reversed('abcdefghijklmnopqrstuvwxyz'):
        if dp[c] == -1:
            continue
        if lc < c:
            continue
        #print(c, dp[lc])
        dp[lc] = max(dp[lc], dp[c] + len(l))
        #print(c, dp[lc])
    dp[lc] = max(dp[lc], len(l))
print(max(dp.values()))