import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }

string COLOR(string s = "") { return "\x1b[" ~ s ~ "m"; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum INF = 10L^^18;

void main() {
  try {
    for (; ; ) {
      const N = readInt;
      const M = readInt;
      auto A = new int[M];
      auto B = new int[M];
      auto C = new long[M];
      foreach (i; 0 .. M) {
        A[i] = readInt - 1;
        B[i] = readInt - 1;
        C[i] = readLong;
      }
      const K = readInt;
      alias XYZ = Tuple!(int, "x", int, "y", int, "z");
      auto T = new XYZ[K];
      foreach (k; 0 .. K) {
        T[k].x = readInt - 1;
        T[k].y = readInt - 1;
        T[k].z = readInt - 1;
      }
      T.sort;
      
      auto G = new int[][N];
      foreach (i; 0 .. M) {
        G[A[i]] ~= i;
      }
      
      alias Entry = Tuple!(long, "c", int, "p");
      auto dp = new Entry[][N];
      dp[0] ~= Entry(0, -1);
      auto cs = new long[N];
      foreach (u; 0 .. N) {
        dp[u].sort;
        auto vs = new RedBlackTree!int;
        foreach (i; G[u]) {
          cs[B[i]] = C[i];
          vs.insert(B[i]);
        }
        foreach (e; dp[u]) {
          auto vvs = new RedBlackTree!int;
          for (int k = T.lowerBound(XYZ(e.p, u, -1)); k < K && T[k].x == e.p && T[k].y == u; ++k) {
            const v = T[k].z;
            if (!vs.equalRange(v).empty) {
              vs.removeKey(v);
              vvs.insert(v);
            }
          }
          foreach (v; vs) {
            dp[v] ~= Entry(e.c + cs[v], u);
          }
          vs = vvs;
        }
      }
      writeln(dp[N - 1] ? dp[N - 1][0].c : -1);
    }
  } catch (EOFException e) {
  }
}