N,M=map(int, input().split()) D=[] for i in range(M): s,t,d=map(int, input().split()) D.append((d,s,t)) D=sorted(D)[::-1] par=[i for i in range(N)] rank=[0]*(N) friend=[0]*N block=[0]*N size=[1]*N def find(x): if par[x]==x: return x else: par[x]=find(par[x]) return par[x] #同じ集合か判定 def same(x,y): return find(x)==find(y) def union(x,y): x=find(x) y=find(y) if x==y: return if rank[x]>rank[y]: par[y]=x size[x]+=size[y] else: par[x]=y size[y]+=size[x] if rank[x]==rank[y]: rank[y]+=1 E=[[]for i in range(N)] limit=10**10 for d,s,t in D: if limit