from collections import defaultdict, deque
from atcoder.scc import SCCGraph


def scc(n: int, adj: dict[int, list[int]]) -> list[list[int]]:
    """グラフを強連結成分分解する。

    Args:
        n: 頂点数
        adj: 隣接リスト {u: [v...]}

    Returns:
        強連結成分のリスト (トポロジカル順)
    """

    g = SCCGraph(n)
    for u, vs in adj.items():
        for v in vs:
            g.add_edge(u, v)

    return g.scc()


MOD = 10**9 + 7
N, M = map(int, input().split())

adj = defaultdict(list)
adj2 = defaultdict(list)
r_adj = defaultdict(list)  # 逆辺
for _ in range(M):
    u, v, l, a = map(int, input().split())
    adj[u].append(v)
    adj2[u].append((v, l, a))

    r_adj[v].append(u)


def calc_reachables():
    reachables = [False] * (N+1)  # 頂点 N へ到達可能な頂点
    reachables[N] = True

    q = deque([N])
    while q:
        v = q.popleft()
        for to in r_adj[v]:
            if reachables[to]: continue
            reachables[to] = True
            q.append(to)

    return reachables


reachables = calc_reachables()

tots = [0] * (N+1)
cnts = [0] * (N+1)
cnts[0] = 1

b = False
cc = scc(N+1, adj)
for g in cc:
    if 0 in g:
        b = True
    if not b: continue

    if len(g) > 1:
        for v in g:
            if reachables[v]:
                print('INF')
                exit()

    for v in g:
        for to, l, a in adj2[v]:
            tots[to] += (tots[v] + cnts[v] * l) * a
            tots[to] %= MOD
            cnts[to] += cnts[v] * a
            cnts[to] %= MOD

ans = tots[N]
print(ans)