N, M = map(int, input().split())
MOD = 10 ** 9 + 7
to = [[] for i in range(N + 1)]
for i in range(M):
    u, v, l, a = map(int, input().split())
    to[u].append([v, l, a, len(to[u])])

used = set()
from collections import deque
qu = deque([0])
dp = [[0, 0] for i in range(N + 1)]
dp[0] = [1, 0]
while len(qu):
    v = qu.popleft()
    for nv, l, a, i in to[v]:
        if (v, nv, i) in used:
            print("INF")
            exit()
        dp[nv][0] = (dp[v][0] * a + dp[nv][0]) % MOD
        dp[nv][1] = ((dp[v][1] + l) * a + dp[nv][1]) % MOD
        used.add((v, nv, i))
        qu.append(nv)
print(dp[N][1])