"""


N～2N回目の間に頂点Nの更新があった場合はOUT
O(N)くらいで何とかする必要が…

Nからさかのぼり、行けない点を全部消す
あとはトポロジカルソートをして数え上げればよい

"""

import sys
from sys import stdin
from collections import deque

N,M = map(int,stdin.readline().split())
mod = 10**9+7

lis = [ [] for i in range(N+1) ]
rlis = [ [] for i in range(N+1) ]
inNum = [0] * (N+1)

for i in range(M):

    u,v,l,a = map(int,stdin.readline().split())
    lis[u].append((v,l,a))
    rlis[v].append(u)

exist = [0] * (N+1)
exist[N] = 1
q = deque([N])

while q:
    v = q.popleft()
    for nex in rlis[v]:
        if 0 == exist[nex]:
            exist[nex] = 1
            q.append(nex)

if not exist[0]:
    print (0)
    sys.exit()

q = deque([0])
exist[0] = 2

while q:
    v = q.popleft()
    for nex,tmp1,tmp2 in lis[v]:
        if 1 == exist[nex]:
            exist[nex] = 2
            q.append(nex)

for v in range(N+1):
    if exist[v] == 2:
        for nex,tmp1,tmp2 in lis[v]:
            inNum[nex] += 1


ans = [[0,0] for i in range(N+1)]
ans[0] = [0,1]

if inNum[0] != 0:
    print ("INF")
    sys.exit()

q = deque([0])

while q:
    
    v = q.popleft()
    if v == N:
        print (ans[N][0])
        #print (ans)
        sys.exit()

    for nex,l,a in lis[v]:
        if exist[nex] != 2:
            continue

        ans[nex][0] += ans[v][0] + ans[v][1] * a * l
        ans[nex][0] %= mod

        ans[nex][1] += ans[v][1] * a
        ans[nex][1] %= mod
        
        inNum[nex] -= 1
        if inNum[nex] == 0:
            q.append(nex)

print ("INF")