import sys
from heapq import heappop as hpp, heappush as hp
def dijkstra(N, s, Edge):
    inf = 10**10
    dist = [inf] * N
    Q = [(0, s)]
    decided = set()
    for _ in range(N):
        while True:
            dn, vn = hpp(Q)
            if vn not in decided:
                decided.add(vn)
                dist[vn] = dn
                break
        for vf, df in Edge[vn]:
            if vf not in decided:
                hp(Q, (dn + df, vf))
    return dist


N, M, P, Q, T = map(int, input().split())
P -= 1
Q -= 1
Edge = [[] for _ in range(N)]
for _ in range(M):
    a, b, c = map(int, sys.stdin.readline().split())
    a -= 1
    b -= 1
    Edge[a].append((b, c))
    Edge[b].append((a, c))

dist0 = dijkstra(N, 0, Edge)
distP = dijkstra(N, P, Edge)
distQ = dijkstra(N, Q, Edge)


ans = -1
for i in range(N):
    for j in range(N):
        t = dist0[i] + dist0[j] + max(distP[i]+distP[j], distQ[i]+distQ[j])
        if t > T:
            continue

        ans = max(ans, dist0[i] + dist0[j] + T - t)
if dist0[P] + distP[Q] + dist0[Q] <= T:
    ans = T
print(ans)