#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=4e5+2;
int n,m,k,u,v,w,p,cnt,ed[N],id[N],fail[N],rt[N],dp[N];
vector<pair<int,int>>g[N];
unordered_map<int,int>son[N];
struct node{int ls,rs,to,w;}t[N];
void insert(int&k,int K,int l,int r,int x,int to,int w){
	k=++cnt,t[k]=t[K];
	if(l==r)return t[k].to=to,t[k].w|=w,void();
	int mid=l+r>>1;
	if(x<=mid)insert(t[k].ls,t[K].ls,l,mid,x,to,w);
	else insert(t[k].rs,t[K].rs,mid+1,r,x,to,w);
}
int query(int k,int l,int r,int x){
	if(!k||l==r)return t[k].to;
	int mid=l+r>>1;
	if(x<=mid)return query(t[k].ls,l,mid,x);
	else return query(t[k].rs,mid+1,r,x);
}
priority_queue<pair<int,int>>Q;
void update(int&k,int l,int r,int w){
	if(!k)return;
	if(l==r){int to=t[k].to;if(!ed[to]&&w+t[k].w<dp[to])Q.push({to,-(dp[to]=w+t[k].w)});
	}else{int mid=l+r>>1;update(t[k].ls,l,mid,w),update(t[k].rs,mid+1,r,w);}
	k=0;
}
signed main(){
	cin>>n>>m>>k;
	for(int i=1;i<=m;i++)cin>>u>>v>>w,g[u].push_back({v,w}),g[v].push_back({u,w});
	for(int i=1;i<=n;i++)id[son[0][i]=++cnt]=i;
	while(k--){cin>>p,u=0;while(p--){cin>>v;if(!son[u][v])son[u][v]=++cnt;id[u=son[u][v]]=v;}ed[u]=1;}
	queue<int>q;cnt=0;
	for(int i=1;i<=n;i++){q.push(i);for(auto j:g[i])insert(rt[i],rt[i],1,n,j.first,j.first,j.second);}
	while(!q.empty()){
		int u=q.front();q.pop();
		ed[u]|=ed[fail[u]];//
		if(!rt[u])rt[u]=rt[fail[u]];
		for(auto i:son[u]){
			int x=i.first,to=i.second;
			insert(rt[u],rt[u],1,n,x,to,0);
			if(son[fail[u]].find(x)!=son[fail[u]].end())fail[to]=son[fail[u]][x];
			else fail[to]=query(rt[fail[u]],1,n,x);
			q.push(to);
		}
	}
	if(ed[1])cout<<-1,exit(0);
	memset(dp,127,sizeof(dp)),Q.push({1,dp[1]=0});
	while(!Q.empty()){
		int u=Q.top().first,w=-Q.top().second;Q.pop();
		if(id[u]==n)cout<<w,exit(0);
		if(w==dp[u])update(rt[u],1,n,w);
	}cout<<-1;
}