import sys

N = int(input())
l = []
for _ in range(N):
    S = input()
    T = list(S)
    if sorted(T) == T:
        l.append((T[-1],T[0],len(T)))
        
now = 'a'
ans = 0
l.sort()
if len(l) == 0:
    print(0)
    exit()
    
for e,s,length in l:
    if now <= s:
        ans += length
        now = e
print(ans)