import sys
from collections import defaultdict, deque
from scipy.sparse.csgraph import connected_components
from scipy.sparse import csr_matrix

input = sys.stdin.buffer.readline


def topological_sort(N, edges):
    outs = defaultdict(list)
    ins = defaultdict(int)
    for v1, v2, in edges:
        outs[v1].append(v2)
        ins[v2] += 1

    q = deque(v1 for v1 in range(N) if ins[v1] == 0)
    while q:
        v1 = q.popleft()
        yield v1
        for v2 in outs[v1]:
            ins[v2] -= 1
            if ins[v2] == 0:
                q.append(v2)


MOD = 10 ** 9 + 7
N, M = map(int, input().split())
edges = [list(map(int, input().split())) for _ in range(M)]

# 強連結成分分解により不要部分を削除
edges_set = set((u, v) for u, v, _, _ in edges)
edges_set.add((N, 0))
frm, to = [], []
for u, v in edges_set:
    frm.append(u)
    to.append(v)
matr = csr_matrix(([1] * len(frm), (frm, to)), shape=(N + 1, N + 1))
_, labels = connected_components(matr, connection='strong')
l0 = labels[0]
nodes = [i for i, x in enumerate(labels) if x == l0]

# 座圧
comp = {x: i for i, x in enumerate(nodes)}
N1 = len(comp)
succ = [[] for _ in range(N1)]
new_edges = set()
for u, v, l, a in edges:
    if u in comp and v in comp:
        cu, cv = comp[u], comp[v]
        succ[cu].append((cv, l, a))
        new_edges.add((cu, cv))

# トポソ
ts = list(topological_sort(N1, new_edges))
if len(ts) != N1: print('INF');exit()

dp = [0] * N1
for v in ts:
    cur = dp[v]
    for s, l, a in succ[v]:
        dp[s] += (cur + l) * a
        dp[s] %= MOD
print(dp[ts[-1]])