import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**5+100)
from collections import *

def bfs():
    dist = [-1]*(N+1)
    dist[0] = 0
    q = deque([0])
    
    while q:
        v = q.popleft()
        
        for nv in g[v]:
            if dist[nv]==-1:
                dist[nv] = dist[v]+1
                q.append(nv)
    
    return dist

def rbfs():
    dist = [-1]*(N+1)
    dist[N] = 0
    q = deque([N])
    
    while q:
        v = q.popleft()
        
        for nv in rg[v]:
            if dist[nv]==-1:
                dist[nv] = dist[v]+1
                q.append(nv)
    
    return dist

def dfs(v, pv):
    global cycle
    
    seen[v] = True
    
    for nv in g[v]:
        if finished[nv]:
            continue
        
        if seen[nv] and not finished[nv]:
            cycle = True
            return

        dfs(nv, v);
        
        if cycle:
            return
    
    finished[v] = True

N, M = map(int, input().split())
G = [[] for _ in range(N+1)]
g = [[] for _ in range(N+1)]
rg = [[] for _ in range(N+1)]

for _ in range(M):
    u, v, l, a = map(int, input().split())
    G[u].append((v, l, a))
    g[u].append(v)
    rg[v].append(u)

dist1, dist2 = bfs(), rbfs()
seen = [False]*(N+1)
finished = [False]*(N+1)
cycle = False
dfs(0, -1)

if cycle:
    print('INF')
    exit()

dpl = [0]*(N+1)
dpc = [0]*(N+1)
dpc[0] = 1
MOD = 10**9+7
q = deque([0])

while q:
    nq = deque([])
    
    while q:
        v = q.popleft()
        
        for nv, l, a in G[v]:
            dpl[nv] += dpl[v]+dpc[v]*a*l
            dpl[nv] %= MOD
            dpc[nv] += dpc[v]*a
            dpc[nv] %= MOD
            nq.append(nv)
    
    q = nq

print(dpl[N])