#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;
#define fi first
#define se second
#define pb push_back

using T = pair<int,ll>;

int main(){
  int n,m;
  cin>>n>>m;

  vector<vector<T>> graph(n+2*m);
  vector<ll> ans(n+2*m,1e18);
  ans[0]=0;
  
  for(int i=0;i<m;i++){
    int k;
    ll c;
    cin>>k>>c;
    graph[n+2*i].pb({n+2*i+1,c});
    for(int j=0;j<k;j++){
      int s;
      cin>>s;
      graph[s-1].pb({n+2*i,(s+1)/2});
      graph[n+2*i+1].pb({s-1,s/2});
    }
  }

  priority_queue<T,vector<T>,greater<T>> que;
  que.push({0,0});

  while(!que.empty()){
    auto [now,dist] = que.top();
    que.pop();

    if(dist>ans[now]){
      continue;
    }

    for(auto [next,dist2] : graph[now]){
      if(ans[now]+dist2<ans[next]){
        que.push({next,dist2});
        ans[next]=ans[now]+dist2;
      }
    }
  }
  
  if(ans[n-1]>=1e18){
    ans[n-1]=-1;
  }
  cout<<ans[n-1]<<endl;
}