rt

#include <bits/stdc++.h>
using namespace std;
const int N=24900;
int n,m,cnt,dis[N],e[N],T;
int h[N],to[N],nxt[N],val[N];
bool vis[N];
void add(int a,int b,int c){
	nxt[++cnt]=h[a];
	to[cnt]=b;
	e[cnt]=c;
	h[a]=cnt;
}
struct node{
	int v,w;
	friend bool operator <(node a,node b){
		return a.v>b.w;
	}
};
priority_queue<node> q;
void Dijkstra(int s){
	for(int i=0;i<=n;i++)
		dis[i]=INT_MAX;
	memset(vis,0,sizeof(vis));
	dis[s]=0;
	q.push({s,0});
	while(!q.empty()){
		int x=q.top().v;
		q.pop();
		if(vis[x]) continue;
		vis[x]=1;
		for(int i=h[x];i;i=nxt[i]){
			int y=to[i];
			if(dis[y]>(long long)dis[x]+val[i]){
				dis[y]=dis[x]+val[i];
				q.push({y,dis[y]});
			}
		}
	}
}
signed main(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++){
		int u,v,w;
		scanf("%d%d%d",&u,&v,&w);
		add(u,v,w);
		add(v,u,w);
	}
	cin>>T;
	while(T--){
		int u,v;
		scanf("%d%d",&u,&v);
		for(int i=h[u];i;i=nxt[i])
			if(to[i]==v) val[i]=e[i];
		for(int i=h[v];i;i=nxt[i])
			if(to[i]==u) val[i]=e[i];
	}
	int s,t;
	scanf("%d%d",&s,&t);
	Dijkstra(s);
	printf("%d\n",dis[t]);
	return 0;
}