while True:
try:
#获取输入的单词数量
N = int(input())
while N:
#获取输入的单词
data = input()
#去重存入字典
d = {}
for word in data:
if word not in d:
d[word] = 1
else:
d[word] = d[word] + 1
d1 = sorted(d.values() ,reverse=True)
ans = 0
m = 0
for word in d1:
ans = ans + (26-m)*word
m = m + 1
print(ans)
N = N - 1
except:
break