#include <array>
#include <queue>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

const int INF = 1012345678;

struct state {
    int pos, cost;
    bool operator<(const state& s) const {
        return cost > s.cost;
    }
};

int main() {
    // step #1. input
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int N, M, K, S, T;
    cin >> M >> N >> K >> S >> T;
    vector<int> A(M), B(M), C(M);
    for (int i = 0; i < M; i++) {
        cin >> A[i] >> B[i] >> C[i];
    }
    vector<array<int, 3> > ban(K);
    for (int i = 0; i < N; i++) {
        cin >> ban[i][0] >> ban[i][1] >> ban[i][2];
    }

    // step #2. construct graph
    vector<vector<int> > G(N);
    for (int i = 0; i < M; i++) {
        G[A[i]].push_back(i);
    }

    // step #3. search ban
    sort(ban.begin(), ban.end());
    auto banned = [&](int x, int y, int z) -> bool {
        return binary_search(ban.begin(), ban.end(), array<int, 3>({x, y, z}));
    };

    // step #4. dijkstra
    vector<int> d(M, INF);
    priority_queue<state> que;
    for (int i = 0; i < M; i++) {
        if (A[i] == S) {
            d[i] = C[i];
            que.push(state{i, C[i]});
        }
    }
    int ans = (T != S ? INF : 0);
    while (!que.empty()) {
        state z = que.top();
        que.pop();
        if (B[z.pos] == T) {
            ans = min(ans, z.cost);
        }
        if (d[z.pos] == z.cost) {
            for (int id : G[B[z.pos]]) {
                if (!banned(A[z.pos], B[z.pos], B[id]) && d[id] > z.cost + C[id]) {
                    d[id] = z.cost + C[id];
                    que.push(state{id, d[id]});
                }
            }
        }
    }

    // step #5. output
    cout << (ans != INF ? ans : -1) << endl;

    return 0;
}