N,M = map(int,input().split())
L = []
for m in range(M):
	line = list(map(int,input().split()))
	L.append(line)
Tri = []
Squ = []
for n in range(N):
	B = [[n]]
	for b in B:
		if len(b) > 4:
			break
		p = b[-1]
		for l in L:
			if p in l:
				p2 = list(set(l) - {p})[0]
				if p2 == n and len(b) == 3 and sorted(b) not in Tri:
					Tri.append(sorted(b))
				if p2 == n and len(b) == 4 and sorted(b) not in Squ:
					Squ.append(sorted(b))
				elif len(b) != 1 and p2 in b:
					pass
				else:
					b.append(p2)
					B.append(b[:])
					b.pop()
			p = b[-1]
count = 0
for s in Squ:
	flag = 0
	for t in Tri:
		if set(t).issubset(set(s)):
			flag = 1
			break
	if flag == 0:
		count = count + 1
print(count)