#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef double db;

const int N = 1 << 18;

set<int> uncomputed[N];
set<PII> s[N];
int col[N];
int from[N], to[N];
int ansForEdge[N];

void f(int i)
{
	if (col[i] == 1)
	{
		cout << "Infinite\n";
		exit(0);
	}
	col[i] = 1;
	int u = from[i], v = to[i];
	while (!uncomputed[v].empty())
	{
		auto it = uncomputed[v].begin();
		if (*it == (i ^ 1))
			it++;
		if (it == uncomputed[v].end())
			break;
		f(*it);
	}
	auto it = prev(s[v].end());
	if (it->S == (i ^ 1))
		it--;
	ansForEdge[i] = it->F + 1;
	col[i] = 2;
	uncomputed[u].erase(i);
	s[u].insert({ansForEdge[i], i});
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	fill(from, from + 2 * m, -1);
	fill(to, to + 2 * m, -1);
	FOR(i, 0, m)
	{
		int u, v, w;
		cin >> u >> v >> w;
		u--;
		v--;
		uncomputed[u].insert(2 * i);
		from[2 * i] = u;
		to[2 * i] = v;
		if (w == 2)
		{
			uncomputed[v].insert(2 * i + 1);
			from[2 * i + 1] = v;
			to[2 * i + 1] = u;
		}
	}
	FOR(v, 0, n)
	{
		s[v].insert({0, -1});
	}
	FOR(v, 0, n)
	{
		while (!uncomputed[v].empty())
		{
			f(*uncomputed[v].begin());
		}
	}
	cout << *max_element(ansForEdge, ansForEdge + 2 * m) << "\n";
	return 0;
}