import heapq

def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    idx = 0
    N = int(data[idx])
    idx += 1
    M = int(data[idx])
    idx += 1
    
    adj = [[] for _ in range(N + 1)]
    
    for _ in range(M):
        k_i = int(data[idx])
        idx += 1
        c_i = int(data[idx])
        idx += 1
        s_i = list(map(int, data[idx:idx + k_i]))
        idx += k_i
        
        s1 = s_i[0]
        for u in s_i:
            w = ((u + s1) + 1) // 2 + c_i
            adj[u].append((s1, w))
            adj[s1].append((u, w))
    
    # Dijkstra's algorithm
    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
        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()