#include<bits/stdc++.h>
using namespace std;

int main(){
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int N, M;
  cin >> N >> M;
  assert(3 <= N && N <= 2e5);
  assert(0 <= M && M <= 2e5);

  vector<vector<pair<int, int>>>g(N);
  for(int i = 0; i < M; i++){
    int u, v, w;
    cin >> u >> v >> w;
    assert(1 <= u && u < v && v <= N);
    assert(1 <= w && w <= 1e9);
    u--; v--;
    g[u].emplace_back(v, w);
  }

  vector<vector<pair<int, int>>>ng(N);
  int K; cin >> K;
  for(int i = 0; i < K; i++){
    int a, b, c;
    cin >> a >> b >> c;
    assert(1 <= a && a < b && b < c && c <= N);
    a--; b--; c--;
    ng[b].emplace_back(a, c);
  }

  vector<vector<pair<long long, int>>>dp(N);
  dp[0].emplace_back(0, -1);
  for(int i = 0; i < N; i++){
    sort(dp[i].begin(), dp[i].end());
    sort(ng[i].begin(), ng[i].end());
    vector<long long>mi(g[i].size(), 1e18);
    int lim = 100;
    for(auto [dist, from]: dp[i]){
      lim--;
      if(lim < 0)break;
      for(int j = 0; j < g[i].size(); j++){
        auto [to, cost] = g[i][j];
        if(binary_search(ng[i].begin(), ng[i].end(), make_pair(from, to)))continue;
        mi[j] = min(mi[j], dist + cost);
      }
    }
    for(int j = 0; j < g[i].size(); j++){
      if(mi[j] != 1e18)dp[g[i][j].first].emplace_back(mi[j], i);
    }
  }
  if(dp[N - 1].empty()){
    cout << -1 << endl;
  }
  else{
    cout << dp[N - 1][0].first << endl;
  }
}