def get_graph(ladders, snakes):
    graph = defaultdict(dict)
    for start, finish in ladders:
        graph[start][finish] = 0
    for start, finish in snakes:
        graph[start][finish] = 0
    return graph
    
def quickestWayUp(ladders, snakes):
    graph = get_graph(ladders, snakes)
    queue = deque()
    queue.append(1)
    costs = dict()
    visited = set([1])
    while queue:
        current_node = queue.popleft()
        neighbours = graph.get(current_node, {current_node + i: 1 for i in range(1, 7)})
        for neighbour in neighbours:
            if neighbour not in visited:
                costs[neighbour] = costs.get(current_node, 0) + neighbours[neighbour]
                visited.add(neighbour)
                queue.append(neighbour)
            if neighbour == 100:
                return costs[neighbour]
    return -1