from heapq import *

N, M, P, Q, T = map(int, input().split())
UV = [list(map(int, input().split())) for _ in range(M)]
E = [[] for _ in range(N)]
P -= 1
Q -= 1
for u, v, c in UV:
    u -= 1
    v -= 1
    E[u].append((v, c))
    E[v].append((u, c))

INF = 10 ** 13  # N * maxコストくらいで設定


# 普通のダイクストラ
def dijkstra(x):
    D = [INF] * N
    D[x] = 0
    q = [(0, x)]
    while q:
        d, u = heappop(q)
        # 下のifでTLE解消することがある
        if d > D[u]: continue
        for i in E[u]:
            a, b = i
            if D[a] > D[u] + b:
                D[a] = D[u] + b
                heappush(q, (D[a], a))
    return D


D0 = dijkstra(0)
DP = dijkstra(P)
DQ = dijkstra(Q)

d0p = D0[P]
d0q = D0[Q]
dpq = DP[Q]

if d0p + d0q + dpq <= T:
    print(T)
    exit()
ans = -1
for x in range(N):
    d0x = D0[x]
    dxp = DP[x]
    dxq = DQ[x]
    for y in range(x, N):
        d0y = D0[y]
        dyp = DP[y]
        dyq = DQ[y]
        mdi = max(dxp + dyp, dxq + dyq)
        if d0x + d0y + mdi <= T:
            ans = max(ans, T - mdi)
print(ans)