N = int(input())
L = []
for i in range(N):
    S = list(input())
    if ''.join(map(str, S)) == ''.join(map(str, sorted(S))):
        L.append(S)
L.sort()
A = [0]*26
for l in L:
    begin = ord(l[0])-97
    end = ord(l[-1])-97
    A[end]=max(A[end],max(A[:begin+1])+len(l))
print(max(A))