from heapq import heappop, heappush

INF = 1 << 60


def dijkstra(s, edge):
    n = len(edge)
    dist = [INF] * n
    dist[s] = 0
    hq = []
    heappush(hq, (dist[s], s))

    while hq:
        dist_v, v = heappop(hq)
        if dist_v > dist[v]:
            continue
        for cost, nx in edge[v]:
            if dist[nx] > dist[v] + cost:
                dist[nx] = dist[v] + cost
                heappush(hq, (dist[nx], nx))
    return dist


N, M, P, Q, T = map(int, input().split())
P -= 1
Q -= 1

G = [[] for _ in range(N)]

for _ in range(M):
    a, b, c = map(int, input().split())
    a -= 1
    b -= 1
    G[a].append((c, b))
    G[b].append((c, a))

dist_0 = dijkstra(0, G)
dist_p = dijkstra(P, G)
dist_q = dijkstra(Q, G)


tmp = dist_0[P] + dist_p[Q] + dist_q[0]
if tmp <= T:
    print(T)
    exit()

ans = -1

for u in range(N):
    for v in range(N):
        tmp = dist_0[u]
        tmp += max(dist_p[u] + dist_p[v], dist_q[u] + dist_q[v])
        tmp += dist_0[v]
        if tmp <= T:
            ans = max(ans, T - max(dist_p[u] + dist_p[v], dist_q[u] + dist_q[v]))

print(ans)