import numpy as np
n = int(input())
lis = []
for _ in range(n):
    a = list(map(str,input()))
    flag = True
    for i in range(len(a)-1):
        if(a[i] > a[i+1]):
            flag = False
            break
    if(flag):
        lis.append(a)

if(len(lis) == 0):
    print(0)
else:
    lis_sort = np.sort(lis,axis=-1)
    i = 0
    j = 1
    ans = len(lis_sort[0])
    while((i < len(lis)) & (j < len(lis))):
        if(lis_sort[i][-1] <= lis_sort[j][0]):
            ans += len(lis_sort[j])
            i = j
        j += 1
    print(ans)