Merkkijonot

from time import time
 
 
'''
def search(lista):
	val = 0
	apu = [0]
	for x in range(1,len(lista)):
		if lista[0] == lista[x]:
			val += 1
			apu.append(x)
	
	apu.sort(reverse=True)
	for i in apu:
		lista.pop(i)
 
	sum = 0
	for i in range(1,val+1):
		sum = sum + i
 
	return  sum
'''
'''
def str2Int(jono):
	apu = []
	val = 0
	for i in range(len(jono)):
		if jono[i] not in apu:
			apu.append(jono[i])
		val += apu.index(jono[i]) << i*8
	return val
'''
'''def strToInt(jono):
	kohta = 0
	apu = ""
	for i in range(len(jono)):
		if jono[i] not in apu:
			apu += jono[i]
	for i in range(len(apu)):
		if kohta < 10:
			jono = jono.replace(apu[i],"0"+str(kohta), len(jono))
			kohta += 1
		else:
			jono = jono.replace(apu[i],str(kohta), len(jono))
			kohta += 1
	return jono
'''
 
'''def harmoniset(lista):
	tulos = 0
	for i in range(len(lista)):
		lista[i] = str2Int(lista[i])
	
	
	
	for i in list(dict.fromkeys(lista)):
		count = lista.count(i)
		tulos += sum(range(1,count))
	return tulos
'''
lista = []
x = input()
 
for i in range(53):
	lista.append([])
 
#with open("data.txt","r") as f:
#	data = f.read()
#	apu = data.split("\n")	
 
#for i in range(len(apu)):
#	lista[len(apu[i])].append(str(apu[i]))
 
for i in range(int(x)):
	x = raw_input()
	lista[len(str(x))].append(str(x))
 
 
summa = 0
 
for i in lista:
	if len(i) < 2:
		continue
	else:
		listanLista = i
		tulos = 0
		
		for j in range(len(listanLista)):
			apu = []
			val = 0
			for k in range(len(listanLista[j])):
				if listanLista[j][k] not in apu:
					apu.append(listanLista[j][k])
				val += apu.index(listanLista[j][k]) << k*8
			listanLista[j] = val
		
 
		for j in list(dict.fromkeys(listanLista)):
			count = listanLista.count(j)
			tulos += sum(range(1,count))	
		summa += tulos 
 
print summa
 

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 5

Group: 3

Verdict: ACCEPTED

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

Test 8

Group: 1, 2, 3

Verdict: ACCEPTED

Test 9

Group: 1, 2, 3

Verdict: ACCEPTED

Test 10

Group: 2, 3

Verdict: ACCEPTED

Test 11

Group: 2, 3

Verdict: ACCEPTED

Test 12

Group: 2, 3

Verdict: ACCEPTED

Test 13

Group: 2, 3

Verdict: ACCEPTED

Test 14

Group: 2, 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 17

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 18

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 19

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 20

Group: 1, 2, 3

Verdict: ACCEPTED

Test 21

Group: 1, 2, 3

Verdict: ACCEPTED

Test 22

Group: 1, 2, 3

Verdict: ACCEPTED

Test 23

Group: 1, 2, 3

Verdict: ACCEPTED

Test 24

Group: 1, 2, 3

Verdict: ACCEPTED