import sys
import heapq

def main():
    input = sys.stdin.read().split()
    ptr = 0
    N = int(input[ptr])
    ptr += 1
    M = int(input[ptr])
    ptr += 1

    adj = [[] for _ in range(N + 1)]

    for _ in range(M):
        k_i = int(input[ptr])
        ptr += 1
        c_i = int(input[ptr])
        ptr += 1
        s = list(map(int, input[ptr:ptr + k_i]))
        ptr += k_i
        s1 = s[0]
        for j in range(1, k_i):
            sj = s[j]
            weight = (s1 + sj + 1) // 2 + c_i
            adj[s1].append((sj, weight))
            adj[sj].append((s1, weight))

    INF = float('inf')
    dist = [INF] * (N + 1)
    dist[1] = 0
    heap = []
    heapq.heappush(heap, (0, 1))

    while heap:
        current_dist, u = heapq.heappop(heap)
        if current_dist > dist[u]:
            continue
        if u == N:
            break
        for v, w in adj[u]:
            if dist[v] > dist[u] + w:
                dist[v] = dist[u] + w
                heapq.heappush(heap, (dist[v], v))

    if dist[N] == INF:
        print(-1)
    else:
        print(dist[N])

if __name__ == '__main__':
    main()