from time import time

import sys
import io, os
sys.setrecursionlimit(10**9)
input = sys.stdin.buffer.readline
#input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

mod = 10**9+7

n, m = map(int, input().split())
ind = [[] for i in range(n+1)]
for i in range(m):
    u, v, l, a = map(int, input().split())
    ind[v].append((u, l, a))

dp = [0]*(n+1)
def dfs(v):
    tt = (time() - stime) / 2.2
    if tt >= 1:
        print('INF')
        exit()
    for u, l, a in ind[v]:
        dfs(u)
        dp[v] += (dp[u]+l)*a
        dp[v] %= mod
stime = time()
dfs(n)
#print(dp)
print(dp[n])