from collections import defaultdict
import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)
inf = 10**18

N, M, K, S, T = map(int, input().split())
if N == 1:
    print(abs(S - T))
    exit()

stair = [[] for _ in range(N+1)]
stair[1].append((S, ~S))
ok = [0] * N
for _ in range(M):
    a, b, c = map(int, input().split())
    ok[a] = 1
    stair[a].append((b, 1))
    stair[a+1].append((c, ~b))


dp = defaultdict(lambda: inf)
dp[S] = 0
for i in range(1, N):
    if not ok[i]:
        print(-1)
        exit()

    ndp = defaultdict(lambda: inf)

    stair[i].sort(key=lambda x: (x[0], x[1]))
    vmin = inf
    for s, f in stair[i]:
        if f >= 0:
            ndp[s] = min(ndp[s], s + vmin)
        else:
            f = ~f
            vmin = min(vmin, dp[f] - s)

    vmin = inf
    stair[i].sort(key=lambda x: (x[0], -x[1]))
    for s, f in stair[i][::-1]:
        if f >= 0:
            ndp[s] = min(ndp[s], s + vmin)
        else:
            f = ~f
            vmin = min(vmin, dp[f] + s)

    dp = ndp

ans = inf
for s, f in stair[N]:
    ans = min(ans, abs(T - s) + dp[~f])
print(ans)