""" 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,l,a)) exist = [0] * (N+1) exist[N] = 1 q = deque([N]) while q: v = q.popleft() for nex,tmp1,tmp2 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 if inNum[0] != 0: print ("INF") sys.exit() ansA = [0 for i in range(N+1)] ansA[0] = 1 q = deque([0]) while q: v = q.popleft() if v == N: break for nex,l,a in lis[v]: if exist[nex] != 2: continue ansA[nex] += ansA[v] * a ansA[nex] %= mod inNum[nex] -= 1 if inNum[nex] == 0: q.append(nex) else: print ("INF") sys.exit() inNum = [0] * (N+1) for v in range(N+1): if exist[v] == 2: for nex,tmp1,tmp2 in rlis[v]: inNum[nex] += 1 ansB = [0 for i in range(N+1)] ansB[N] = 1 q = deque([N]) while q: v = q.popleft() for nex,l,a in rlis[v]: if exist[nex] != 2: continue ansB[nex] += ansB[v] * a ansB[nex] %= mod inNum[nex] -= 1 if inNum[nex] == 0: q.append(nex) ans = 0 for v in range(N+1): if 2 == exist[v]: for nex,l,a in lis[v]: if 2 == exist[nex]: ans += ansA[v] * a * ansB[nex] * l ans %= mod #print (ansA,ansB) print (ans)