/* -*- coding: utf-8 -*-
 *
 * 1480.cc:  No.1480 Many Complete Graphs - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100000;
const int MAX_M = 100000;
const int MAX_GN = MAX_N + MAX_M * 2;
const long long LINF = 1LL << 62;

/* typedef */

typedef long long ll;
typedef pair<ll,int> pli;
typedef pair<int,int> pii;
typedef vector<pii> vpii;

/* global variables */

vpii nbrs[MAX_GN];
ll ds[MAX_GN];

/* subroutines */

/* main */

int main() {
  int n, m;
  scanf("%d%d", &n, &m);

  for (int i = 0; i < m; i++) {
    int t0 = n + i * 2, t1 = t0 + 1;
    nbrs[t0].push_back(pii(t1, 1));
    nbrs[t1].push_back(pii(t0, 1));

    int ki, ci;
    scanf("%d%d", &ki, &ci);
    for (int j = 0; j < ki; j++) {
      int sj;
      scanf("%d", &sj);
      sj--;
      int tj = (sj & 1) ? t1 : t0;
      int wj = sj + 1 + ci;
      nbrs[sj].push_back(pii(tj, wj));
      nbrs[tj].push_back(pii(sj, wj));
    }
  }

  int gn = n + m * 2, st = 0, gl = n - 1;
  fill(ds, ds + gn, LINF);
  ds[st] = 0;

  priority_queue<pli> q;
  q.push(pli(0, st));

  while (! q.empty()) {
    pli u = q.top(); q.pop();
    ll ud = -u.first;
    int ui = u.second;
    if (ds[ui] != ud) continue;
    if (ui == gl) break;

    vpii &nbru = nbrs[ui];
    for (vpii::iterator vit = nbru.begin(); vit != nbru.end(); vit++) {
      int vi = vit->first;
      ll vd = ud + vit->second;
      if (ds[vi] > vd) {
	ds[vi] = vd;
	q.push(pli(-vd, vi));
      }
    }
  }

  printf("%lld\n", (ds[gl] >= LINF) ? -1 : ds[gl] / 2);
  return 0;
}