#include <bits/stdc++.h>

using namespace std;

using state = tuple<long long, int, int>;   // (cost, tou, kai)

const int MAX = 2e5 + 10;
int N, M, S, T;
long K;
vector<pair<int, long long>> G[MAX];
unordered_map<int, long long> mp[MAX];   //[tou][kai] = minCost

int main() {
    scanf("%d%d%lld%d%d", &N, &M, &K, &S, &T);
    S--;T--;K--;
    for (int i = 0; i < M; i++) {
        int a, b, c;
        scanf("%d%d%d", &a, &b, &c);
        a--;b--;c--;
        G[a].emplace_back(b, c);
    }
    priority_queue<state, vector<state>, greater<state>> pq;
    pq.emplace(0, 0, S);
    const long long inf = 1e18;
    long long ans = inf;
    while (!pq.empty()) {
        long long cost;
        int tou, kai;
        tie(cost, tou, kai) = pq.top();
        pq.pop();
        if (tou == N - 1) {
            ans = min(ans, cost + llabs(kai - T));
        }
        if (mp[tou].count(kai)) {
            continue;
        }
        mp[tou][kai] = cost;
        for (auto&& e : G[tou]) {
            if (mp[tou + 1].count(e.second) && mp[tou + 1][e.second] <= cost + llabs(e.first - kai)) {
                continue;
            }
            pq.emplace(cost + llabs(e.first - kai), tou + 1, e.second);
        }
    }
    cout << (ans == inf ? -1 : ans) << endl;
    return 0;
}