#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define X first
#define Y second
#define ALL(v) v.begin(), v.end()
#define pb push_back
#define SZ(a) ((int)a.size())

const ll INF = 1e18;

struct Edge {
    int u, v, w;
} edges[300005];

vector<int> G[30005];
ll dis[300005];
unordered_set<ll> ban;

ll num(ll a, ll b, ll c) {
    const ll P = 100000;
    return a * P * P + b * P + c; 
}

bool valid(ll a, ll b, ll c) {
    return ban.find(num(a, b, c)) == ban.end();
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    int n, m, k, s, t;
    cin >> m >> n >> k >> s >> t, ++s, ++t;
    for (int i = 1; i <= m; ++i) {
        cin >> edges[i].u >> edges[i].v >> edges[i].w;
        ++edges[i].u, ++edges[i].v;
        G[edges[i].u].pb(i);
    }
    while (k--) {
        int a, b, c;
        cin >> a >> b >> c;
        ban.insert(num(a + 1, b + 1, c + 1));
    }
    priority_queue<pll, vector<pll>, greater<pll>> pq;
    fill_n(dis + 1, m, INF);

    auto relax = [&](int e, ll d) {
        if (dis[e] > d) {
            dis[e] = d;
            pq.push(pll(d, e));
        }
    };

    for (int e : G[s])
        relax(e, edges[e].w);

    while (!pq.empty()) {
        auto [d, e] = pq.top();
        pq.pop();
        if (dis[e] != d) continue;
        for (int i : G[edges[e].v])
            if (valid(edges[e].u, edges[e].v, edges[i].v))
                relax(i, dis[e] + edges[i].w);
    }

    ll ans = INF;
    for (int i = 1; i <= m; ++i)
        if (edges[i].v == t)
            ans = min(ans, dis[i]);

    if (ans == INF) cout << "-1\n";
    else cout << ans << "\n";
}