import sys
def input():
	return sys.stdin.buffer.readline()[:-1]

n, m = map(int, input().split())
if not (1 <= n <= 200000):
	raise ValueError
rs = set()
for _ in range(m):
	l, r, p = map(int, input().split())
	if l > r:
		raise ValueError
	if not (1 <= l <= n) or not (1 <= r <= n) or not (-1 <= p <= 1):
		raise ValueError
	rs.add(r)
if len(rs) != m:
	raise ValueError

print(0)