n=int(input())
lis=[]
ch='abcdefghijklmnopqrstuvwxyz'
for _ in range(n):
    s=input()
    tmp=[]
    for i in range(len(s)):
        tmp.append(ch.index(s[i]))
    f=True
    for i in range(len(s)-1):
        if s[i]>s[i+1]:
            f=False
            break
    if f:
        lis.append(tmp)
if len(lis)==0:
    exit(print(0))
L=[]
for t in lis:
    L.append((t[0],t[-1],len(t)))
L.sort()
N=len(L)
dp=[[0]*26 for _ in range(N+1)]
for i in range(N):
    l,r,d=L[i][0],L[i][1],L[i][2]
    for k in range(l+1):
        dp[i+1][r]=max(dp[i][r],dp[i][k]+d,dp[i+1][r])
    for j in range(26):
        dp[i+1][j]=max(dp[i+1][j],dp[i][j])
print(max(dp[-1]))