// #pragma GCC target("avx2")
#pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
using namespace std;

using P = pair<int, int>;

const int M = 998244353;
const long long LM = 1LL << 60;


int main() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    int n, m;
    cin >> n >> m;
    vector<vector<pair<long long, int>>> edge(n);
    for (int i = 0; i < m; ++i) {
        int u, v;
        long long w;
        cin >> u >> v >> w;
        --u;
        --v;
        edge[u].emplace_back(w, v);
    }
    int k;
    cin >> k;
    unordered_map<long long, unordered_set<int>> banned;
    for (int i = 0; i < k; ++i) {
        int a, b, c;
        cin >> a >> b >> c;
        --a;
        --b;
        --c;
        if (!banned.count(a * (long long)M + b)) {
            banned[a * (long long)M + b] = unordered_set<int>();
        }
        banned[a * (long long)M + b].insert(c);
    }
    long long ans = -1;
    priority_queue<pair<long long, long long>, vector<pair<long long, long long>>, greater<pair<long long, long long>>> pq;
    pq.emplace(0LL, 0LL);

    while (!pq.empty()) {
        auto p = pq.top();
        pq.pop();
        int now = p.second % M;
        if (now == n - 1) {
            ans = p.first;
            break;
        }
        vector<pair<long long, int>> rem;
        for (auto& e : edge[now]) {
            if (banned.count(p.second) && banned[p.second].count(e.second)) {
                rem.push_back(e);
            }
            else {
                pq.emplace(e.first + p.first, now * (long long)M + e.second);
            }
        }
        edge[now] = rem;
    }

    cout << ans << '\n';

    return 0;
}