//
#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define lch (o << 1)
#define rch (o << 1 | 1)

typedef double db;
typedef long long ll;
typedef unsigned int ui;
typedef pair<int, int> pint;
typedef tuple<int, int, int> tint;

const int N = 1e5 + 5;
const int MOD = 1e9 + 7;
const int INF = 0x3f3f3f3f;
const ll INF_LL = 0x3f3f3f3f3f3f3f3f;

struct Adj {
	int v, w, s;
};

int ind[N];
vector<Adj> a[N];
bool ok[N];

void dfs(int u) {
	ok[u] = 1;
	for (auto e: a[u]) {
		if (ok[e.v]) continue;
		dfs(e.v);
	}
}

ll sumLS[N], sumS[N];

int main() {
	ios::sync_with_stdio(0);

	int n, m;
	cin >> n >> m;
	for (int i = 1; i <= m; i++) {
		int u, v, w, s;
		cin >> u >> v >> w >> s;
		a[u].push_back((Adj){v, w, s});
	}

	dfs(0);
	for (int u = 0; u <= n; u++) {
		if (!ok[u]) continue;
		for (auto e: a[u])
			ind[e.v]++;
	}

	if (ind[0] > 0) {
		cout << "INF" << endl;
		return 0;
	}

	// topo
	queue<int> q;
	q.push(0);
	sumS[0] = 1;

	while (!q.empty()) {
		int u = q.front();
		q.pop();
		for (auto e: a[u]) {
			ind[e.v]--;
			if (ind[e.v] == 0)
				q.push(e.v);

			// cal
			sumLS[e.v] = (sumLS[e.v] + sumLS[u] * e.s + sumS[u] * e.w % MOD * e.s) % MOD;
			sumS[e.v] = (sumS[e.v] + sumS[u] * e.s) % MOD;
		}
	}

	bool flag = 0;
	for (int i = 0; i <= n; i++)
		if (ok[i] && ind[i])
			flag = 1;
	if (flag) {
		cout << "INF" << endl;
		return 0;
	}

	ll ans = sumLS[n];
	ans = (ans % MOD + MOD) % MOD;
	cout << ans << endl;

	return 0;
}