class Graph(): def __init__(self,size,directed=False): self.dir=directed self.size=size self.gr=[[] for i in range(size)] self.edges=[] def add_edge(self,u,v,status={}): self.gr[u].append(self.Edge(u,v,status)) if not(self.dir): self.gr[v].append(self.Edge(v,u,status)) self.edges.append(self.Edge(u,v,status)) def node(self,v): return self.gr[v] def __getitem__(self,v): return self.gr[v] class Edge(): def __init__(self,st,to,status): self.st=st self.to=to self.status=status def __getitem__(self,val): return self.status[val] inf=pow(2,61)-1 from heapq import heappop,heappush def dijkstra(graph,start,weight): dist=[inf for i in range(graph.size)] used=[False for i in range(graph.size)] dist[start]=0 vert=[(0,start)] while len(vert)>0: dis,pos=heappop(vert) if used[pos]: continue used[pos]=True for i in graph.node(pos): if dis+weight(i)<dist[i.to]: heappush(vert,(dis+weight(i),i.to)) dist[i.to]=dis+weight(i) return dist N,M=map(int,input().split()) gr=Graph(N,directed=True) rev=Graph(N,directed=True) for i in range(M): u,v,t=map(int,input().split()) gr.add_edge(u-1,v-1,t) rev.add_edge(v-1,u-1,t) w=lambda x:x.status d1=dijkstra(gr,N-2,w) d2=dijkstra(gr,N-1,w) d3=dijkstra(rev,N-2,w) d4=dijkstra(rev,N-1,w) for i in range(N-2): ans=min(d3[i]+d1[N-1]+d2[i],d4[i]+d2[N-2]+d1[i]) if ans>=inf: print(-1) else: print(ans)