#include <iostream>
#include <vector>
#include <string>
#include <queue>
using namespace std;
using ll=long long;
using ull=unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

template<class E> using nega_queue = priority_queue<E,vector<E>,greater<E>>;

const ll INF = 1001001001001001001;

struct Edge{ int to; ll d; };

int N,M;
vector<vector<Edge>> E;
vector<ll> D;

int main(){
  scanf("%d%d",&N,&M);
  E.resize(N+M);
  rep(i,M){
    int k,c; scanf("%d%d",&k,&c);
    rep(kk,k){
      int s; scanf("%d",&s);
      E[s-1].push_back({N+i,s+c});
      E[N+i].push_back({s-1,s+c});
    }
  }

  D.assign(N+M,INF);
  nega_queue<pair<ll,int>> Q;
  D[0]=0; Q.push({0,0});
  while(Q.size()){
    ll d = Q.top().first;
    int p = Q.top().second; Q.pop();
    if(D[p]!=d) continue;
    for(auto e : E[p]){
      ll nxd = D[p] + e.d;
      if(e.to<N) if(nxd%2==1) nxd++;
      if(D[e.to]<=nxd) continue;
      D[e.to] = nxd; Q.push({nxd,e.to});
    }
  }


  if(D[N-1] == INF) printf("-1\n");
  else printf("%lld\n",D[N-1]/2);
  return 0;
}