from scipy.sparse import csr_matrix
from scipy.sparse.csgraph import dijkstra
import numpy as np
import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)

N, M, P, Q, T = map(int, input().split())
A, B, C = np.array([input().split() for _ in range(M)], dtype=np.int64).T

G = csr_matrix((C, (A-1, B-1)), shape=(N, N))
path = (dijkstra(G, directed=False) + 0.01).astype(np.int64)

# ぜんぶ2人で回る
t = path[0][P-1] + path[P-1][Q-1] + path[Q-1][0]
if t <= T:
    print(T)
    exit()

ans = 0
same = path[0, :]
toP = path[:, P-1]
toQ = path[:, Q-1]
time = 2 * (same + np.maximum(toP, toQ))
wait = np.maximum(0, T - time)
if (time > T).all():
    print(-1)
    exit()

ans = (2 * same + wait)[time <= T].max()
print(ans)