import heapq


def dijkstra(s, graph):
    n = len(graph)-1
    dist = [float("inf") for i in range(n+1)]
    dist[s] = 0
    pq = []
    heapq.heapify(pq)
    heapq.heappush(pq, (0, s))
    while pq:
        mini_dis, node = heapq.heappop(pq)
        if dist[node] < mini_dis:
            continue
        for w, point in graph[node]:
            if dist[point] < w:
                continue
            newlen = dist[node]+w
            if newlen < dist[point]:
                heapq.heappush(pq, (newlen, point))
                dist[point] = newlen
    return dist

N,M,P,Q,T = map(int,input().split())
l = [[] for _ in range(N+1)] 
for _ in range(M):
  a,b,c = map(int,input().split())
  l[a].append((c,b))
  l[b].append((c,a))
  
A = dijkstra(1,l)
B = dijkstra(P,l)
C = dijkstra(Q,l)
ans = -1
if (A[P]+A[Q]+C[1]) <= T:
  print(T)
  exit()
for i in range(1,N+1):
  for j in range(1,N+1):
    if A[i]+B[i]+A[j]+B[j] <= T and A[i]+C[i]+A[j]+C[j] <= T:
      ans = max(ans,T-max(B[i]+B[j],C[i]+C[j]))

print(ans)