while True:
try:
num_name = int(input())
name_list=[]
for i in range(num_name):
name = str(input()).lower()
name_character_list = list(set(name))
sorted_character_list = sorted(name_character_list,key=lambda x: name.count(x),reverse=True)
beauty_score =0
for i,character in enumerate(sorted_character_list):
beauty_score = beauty_score + name.count(character)*(26-i)
print(beauty_score)
except:
break