/* -*- coding: utf-8 -*-
 *
 * 1364.cc:  No.1364 [Renaming] Road to Cherry from Zelkova - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100000 + 1;
const int MAX_M = 200000;
const int MOD = 1000000007;

/* typedef */

typedef long long ll;
typedef queue<int> qi;
typedef pair<int,int> pii;
typedef vector<pii> vpii;

/* global variables */

int ls[MAX_M], as[MAX_M];
vpii nbrs[MAX_N];
int ps[MAX_N], cis[MAX_N], pns[MAX_N];
bool used[MAX_N], pts[MAX_N], lps[MAX_N], lpes[MAX_M];
int ds[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, m;
  scanf("%d%d", &n, &m);

  for (int i = 0; i < m; i++) {
    int u, v;
    scanf("%d%d%d%d", &u, &v, ls + i, as + i);
    nbrs[u].push_back(pii(v, i));
  }

  ps[0] = -1;
  used[0] = true;
  for (int u = 0; u >= 0;) {
    vpii &nbru = nbrs[u];
    if (cis[u] == 0) pts[u] = true;
    if (cis[u] < nbru.size()) {
      pii pv = nbru[cis[u]++];
      int v = pv.first, ei = pv.second;

      if (pts[v]) lps[v] = lpes[ei] = true;
      else {
	pns[v]++;
	if (! used[v]) {
	  ps[v] = u;
	  used[v] = true;
	  u = v;
	}
      }
    }
    else {
      pts[u] = false;
      u = ps[u];
    }
  }
  //for (int i = 0; i <= n; i++) printf("%d", lps[i]); putchar('\n');

  ds[0] = 0;
  qi q;
  q.push(0);

  while (! q.empty()) {
    int u = q.front(); q.pop();
    if (u == n) break;

    vpii &nbru = nbrs[u];
    for (vpii::iterator vit = nbru.begin(); vit != nbru.end(); vit++) {
      int v = vit->first, ei = vit->second;
      if (! lpes[ei]) {
	lps[v] = (lps[v] || lps[u]);
	ds[v] = (ds[v] + (ll)(ds[u] + ls[ei]) % MOD * as[ei] % MOD) % MOD;
	if (--pns[v] == 0) q.push(v);
      }
    }
  }
  //for (int i = 0; i <= n; i++) printf("%d", lps[i]); putchar('\n');

  if (lps[n]) puts("INF");
  else printf("%d\n", ds[n]);
  return 0;
}