import heapq


def dijkstra(s, graph):
    n = len(graph)-1
    dist = [10**15 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())
graph = [[] for i in range(N+1)]
for i in range(M):
    a, b, c = map(int, input().split())
    graph[a].append((c, b))
    graph[b].append((c, a))
data = [[]]
# めちゃめちゃ重い計算量 N**2 log M
for i in range(1, N+1):
    data.append(dijkstra(i, graph))
ans = -1
for i in range(1, N+1):
    if 2*data[1][i]+2*data[i][P] <= T and 2*data[1][i] + 2*data[i][Q] <= T:
        ans = max(ans, T-max(2*data[i][P], 2*data[i][Q]))
    if 2*data[1][i]+2*data[i][P] +2*data[i][Q]<=T:
        ans = T
print(ans)