// 距离退役还有 44 天
#include<cstdio>
#include<iostream>
#include<queue>
#include<vector>
#include<ctime>
#define eb emplace_back
using namespace std;
namespace IO{
	template<typename T> inline void rd(T &x){
		x=0; bool f=0; char c=getchar();
		while(c<'0'||c>'9') f|=c=='-',c=getchar();
		while('0'<=c&&c<='9') x=((x<<3)+(x<<1))+(c^48),c=getchar();
		x=f?-x:x;
	}
	template<typename T,typename ...Args> inline void rd(T &x,Args &...args){ rd(x),rd(args...); }
	template<typename T> inline void wt(char c,T x){
		static int stk[114]; int top=0;
		if(x<0) x=-x,putchar('-');
		do stk[++top]=x%10,x/=10; while(x);
		while(top) putchar(stk[top--]+'0');
		putchar(c);
	}
	template<typename T,typename ...Args> inline void wt(char c,T x,Args ...args){ wt(c,x),wt(c,args...); }
	template<typename T,typename ...Args> inline void wt(char c1,char c2,T x,Args ...args){ wt(c2,x),wt(c2,args...),putchar(c1); }
}
using IO::rd;
using IO::wt;
typedef pair<int,int> PII;
const int INF=1e9;
const int N=1007;
int n,m,K;
int tr[N][N],val[N],ne[N],idx;
bool flag[N];
int p[N],cnt;
vector<PII>g[N];
inline void ins(int x){
	int u=0;
	for(int i=1;i<=cnt;i++){
		if(!tr[u][p[i]]) tr[u][p[i]]=++idx;
		u=tr[u][p[i]],val[u]=p[i];
	}
	flag[u]=x;
}
inline void build(){
	queue<int>q;
	for(int i=1;i<=n;i++){
		if(tr[0][i]) q.push(tr[0][i]);
	}
	while(q.size()){
		int u=q.front(); q.pop();
		for(int i=1;i<=n;i++){
			int &v=tr[u][i];
			if(!tr[u][i]) v=tr[ne[u]][i];
			else{
				ne[v]=tr[ne[u]][i];
				q.push(v);
			}
		}
	}
}
int dist[N];
inline int dij(int S){
	for(int i=0;i<=idx;i++) dist[i]=INF;
	priority_queue<PII>q;
	dist[S]=0,q.push({0,S});
	int ans=INF;
	while(q.size()){
		int u=q.top().second; q.pop();
		if(flag[u]) continue;
		flag[u]=1;
		for(PII A:g[val[u]]){
			int v=tr[u][A.first],w=A.second;
			if(flag[v]) continue;
			if(dist[v]>dist[u]+w){
				dist[v]=dist[u]+w,q.push({-dist[v],v});
				if(val[v]==n) ans=min(ans,dist[v]);
			}
		}
	}
	return ans;
}
int main(){
#ifndef ONLINE_JUDGE
	freopen("in.in","r",stdin);
	freopen("out.out","w",stdout);
#endif
	rd(n,m,K);
	for(int i=1;i<=m;i++){
		int u,v,w; rd(u,v,w);
		g[u].eb(v,w);
	}
	while(K--){
		rd(cnt);
		for(int i=1;i<=cnt;i++) rd(p[i]);
		ins(1);
	}
	for(int i=1;i<=n;i++) p[cnt=1]=i,ins(0);
	build();
	wt('\n',dij(tr[0][1]));
	// for(int i=0;i<=idx;i++) cerr<<flag[i]<<" ";
	return 0;
}