#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define fi first
#define se second
const ll mod=998244353;
const int N=2e5+5;
ll n,m,k,z,y;
int eu[N],ev[N];
ll ew[N];
ll d[N];
vector<pair<int,int> >in[N],out[N];
int sz=0;
vector<int>g[N];
map<int,vector<int> >ban[N];

ll jp[N];


ll mn[1<<19];
void build(int id,int l,int r){
	if(l==r){
		mn[id]=d[in[y][l-1].se];
		return;
	}
	int mid=(l+r)/2;
	build(id*2,l,mid);
	build(id*2+1,mid+1,r);
	mn[id]=min(mn[id*2],mn[id*2+1]);
}
ll qry(int id,int l,int r,int ql,int qr){
	if(l>qr || r<ql) return 1e18;
	if(ql<=l && r<=qr) return mn[id];
	int mid=(l+r)/2;
	return min(qry(id*2,l,mid,ql,qr),qry(id*2+1,mid+1,r,ql,qr));
}
int main(){
	ios::sync_with_stdio(false);cin.tie(0);
	cin >> n >> m;
	for(int i=1; i<=m ;i++){
		int u,v;ll w;cin >> u >> v >> w;
		eu[i]=u;ev[i]=v;ew[i]=w;
		in[v].push_back({u,i});
		out[u].push_back({v,i});
		d[i]=1e18;
	}
	in[1].push_back({0,0});
	cin >> k;
	for(int i=1; i<=k ;i++){
		int a,b,c;cin >> a >> b >> c;
		ban[b][c].push_back(a);
	}
	ll res=1e18;
	for(int i=1; i<=n ;i++){
		if(in[i].empty()) continue;
		y=i;
		sort(in[i].begin(),in[i].end());
		z=in[i].size();
		for(int j=0; j<in[i].size() ;j++){
			jp[in[i][j].fi]=j+1;
		}
		build(1,1,z);
		for(auto c:out[i]){
			auto &v=ban[i][c.fi];
			vector<int>g;
			for(auto d:v){
				if(jp[d]!=0) g.push_back(jp[d]);
			}
			sort(g.begin(),g.end());
			int prv=0;
			ll cur=1e18;
			for(auto d:g){
				if(prv+1<d) cur=min(cur,qry(1,1,z,prv+1,d-1));
				prv=d;
			}
			if(prv+1<=z) cur=min(cur,qry(1,1,z,prv+1,z));
			d[c.se]=cur+ew[c.se];
			if(c.fi==n) res=min(res,d[c.se]);
		}
	}
	if(res==1e18) res=-1;
	cout << res << '\n';
}