N,M = map(int,input().split())
G = [[] for _ in range(N + 1 + M)]
for i in range(M):
    l = list(map(int,input().split()))
    for k in range(2,len(l)):
        G[l[k]].append(N + i + 1)
        G[N + i + 1].append((l[k],l[1]))

import heapq
q = []
heapq.heapify(q)
heapq.heappush(q,(0,1))
C = 10 ** 16
dist = [C] * (N + 1)
dist[1] = 0
import sys
while len(q):
    d,i = heapq.heappop(q)
    if i == N:
        print(d)
        exit()
    if d > dist[i]:
        continue
    for m in G[i]:
        for s,c in G[m]:
            u = (i + s + 1) // 2 + c + dist[i]
            if u < dist[s]:
                dist[s] = u
                heapq.heappush(q,(u,s))
print(-1)