import sys input=sys.stdin.readline n,m=map(int,input().split()) aby=[] for _ in range(m): a,b=map(int,input().split()) y=int(input()) aby.append([a,b,y]) g=[[] for _ in range(n)] for a,b,y in aby: a,b=a-1,b-1 g[a].append([b,y]) g[b].append([a,y]) x=[0]*n flg=True for i in range(30): seen=[-1]*n for d in (0,1): flg=True seen[0]=d todo=[0] while todo: v=todo.pop() for nv,y in g[v]: if seen[nv]==-1: seen[nv]=seen[v]^(y>>i)&1 todo.append(nv) elif seen[nv]==seen[v]^(y>>i)&1: continue else: flg=False break if flg: for v in range(n): if seen[v]==1: x[v]+=1<