/// tban lecodes el bosta2
#pragma GCC optimize("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2,fma")
#include "bits/stdc++.h"
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;


#define pb push_back
#define F first
#define S second
#define f(i, a, b)  for(int i = a; i < b; i++)
#define all(a)  a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define sz(x) (int)(x).size()
#define mp(x,y) make_pair(x,y)
#define popCnt(x) (__builtin_popcountll(x))
#define int ll

using ll = long long;
using ii = pair<int, int>;
using ull = unsigned long long;
const int N = 5e5+5, LG = 18, MOD = 1e9+7;
const long double PI = acos(-1);
const long double EPS = 1e-7;

int n, m, k;

vector<pair<int, ii>> adj[N];
map<ii, int> mp;
map<ii, int> go;
void doWork() {

    cin >> n >> m >> k;


    while(m--) {
        int u, v, w;
        cin >> u >> v >> w;
        int k;
        cin >> k;
        f(i,0,k) {
            int x;
            cin >> x;
            adj[v].pb({u, ii(w, x)});
            mp[{u,x}] += 1;
        }
    }

    priority_queue<ii> pq;
    vector<ll> dist(n + 1, LLONG_MAX);
    vector<bool> vis(n+1);
    dist[n] = 0;
    pq.push({0,n});
    while(pq.size()) {
        auto node = pq.top().second;
        pq.pop();
        if(vis[node]) continue;
        vis[node]=true;
        for(auto v : adj[node]) {
            mp[{v.F,v.S.S}] -= 1;
            go[{v.F,v.S.S}] = max(go[{v.F,v.S.S}], dist[node]+v.S.F);
            if(!mp[{v.F,v.S.S}] && dist[v.F] > go[{v.F,v.S.S}]) {   ///assign ya kossomk
                dist[v.F] = go[{v.F,v.S.S}];
                pq.push({-dist[v.F], v.F});
            }
        }
    }

    if(dist[1] == LLONG_MAX)
        cout << "impossible\n";
    else
        cout << dist[1] << '\n';


}
int32_t main() {
#ifdef ONLINE_JUDGE
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#endif // ONLINE_JUDGE

    int t = 1;
//    cin >> t;
    while (t--) {
        doWork();
    }
    return 0;
}