using System; using static System.Console; using System.Linq; using System.Collections.Generic; class Program { static int NN => int.Parse(ReadLine()); static int[] NList => ReadLine().Split().Select(int.Parse).ToArray(); static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray(); static string[] SList(long n) => Enumerable.Repeat(0, (int)n).Select(_ => ReadLine()).ToArray(); public static void Main() { Solve(); } static void Solve() { var c = NList; var (n, m) = (c[0], c[1]); var map = NArr(m); var tree = new List<(int to, long len)>[n + 4 * m + 1]; for (var i = 0; i < tree.Length; ++i) tree[i] = new List<(int to, long len)>(); for (var i = 0; i < m; ++i) { var ci = map[i][1]; for (var j = 2; j < map[i].Length; ++j) { if (map[i][j] % 2 == 0) { tree[map[i][j]].Add((n + 4 * i + 1, map[i][j] / 2)); tree[n + 4 * i + 3].Add((map[i][j], map[i][j] / 2)); } else { tree[map[i][j]].Add((n + 4 * i + 2, map[i][j] / 2)); tree[n + 4 * i + 4].Add((map[i][j], (map[i][j] + 1) / 2)); } } tree[n + 4 * i + 1].Add((n + 4 * i + 3, ci)); tree[n + 4 * i + 1].Add((n + 4 * i + 4, ci)); tree[n + 4 * i + 2].Add((n + 4 * i + 3, ci + 1)); tree[n + 4 * i + 2].Add((n + 4 * i + 4, ci)); } var INF = long.MaxValue / 2; var len = Enumerable.Repeat(INF, tree.Length).ToArray(); len[1] = 0; var q = new PriorityQueue(n, false); q.Enqueue(new Pair(1, 0)); while (q.Count > 0) { var cur = q.Dequeue(); if (len[cur.Pos] != cur.Val) continue; foreach (var next in tree[cur.Pos]) { if (len[next.to] <= cur.Val + next.len) continue; len[next.to] = cur.Val + next.len; q.Enqueue(new Pair(next.to, len[next.to])); } } WriteLine(len[n] == INF ? -1 : len[n]); } class Pair : IComparable { public int Pos; public long Val; public Pair(int pos, long val) { Pos = pos; Val = val; } public int CompareTo(Pair b) { return Val.CompareTo(b.Val); } } class PriorityQueue where T : IComparable { public T[] List; public int Count; bool IsTopMax; public PriorityQueue(int count, bool isTopMax) { IsTopMax = isTopMax; List = new T[Math.Max(128, count)]; } public void Enqueue(T value) { if (Count == List.Length) { var newlist = new T[List.Length * 2]; for (var i = 0; i < List.Length; ++i) newlist[i] = List[i]; List = newlist; } var pos = Count; List[pos] = value; ++Count; while (pos > 0) { var parent = (pos - 1) / 2; if (Calc(List[parent], List[pos], true)) break; Swap(parent, pos); pos = parent; } } public T Dequeue() { --Count; Swap(0, Count); var pos = 0; while (true) { var child = pos * 2 + 1; if (child >= Count) break; if (child + 1 < Count && Calc(List[child + 1], List[child], false)) ++child; if (Calc(List[pos], List[child], true)) break; Swap(pos, child); pos = child; } return List[Count]; } bool Calc(T a, T b, bool equalVal) { var ret = a.CompareTo(b); if (ret == 0 && equalVal) return true; return IsTopMax ? ret > 0 : ret < 0; } void Swap(int a, int b) { var tmp = List[a]; List[a] = List[b]; List[b] = tmp; } } }