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)]  # 1-based

    for _ in range(M):
        k = int(input[ptr])
        ptr += 1
        c = int(input[ptr])
        ptr += 1
        s = list(map(int, input[ptr:ptr + k]))
        ptr += k
        s0 = s[0]
        for u in s:
            # Add edge u <-> s0
            w = ((u + s0) + 1) // 2 + c
            adj[u].append((s0, w))
            adj[s0].append((u, w))

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

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

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

if __name__ == '__main__':
    main()