N = int(input())
S = []
T = []
for _ in range(N):
	S.append(input())
for i, s_a in enumerate(S):
	for k, s_b in enumerate(S):
		if i == k:
			continue
		if s_a+s_b not in T:
			T.append(s_a+s_b)

print(len(T))