def toboggan_run(tree_map, move):
    """ execute toboggan run and return trees found """
    pos_x = 0
    pos_y = 0
    tree_count = 0

    while True:
        pos_x += move[0]
        pos_x = pos_x % tree_map["max_x"]
        pos_y += move[1]

        if pos_y >= tree_map["max_y"]:
            break

        if (pos_x, pos_y) in tree_map:
            tree_count += 1

    print("for move", move, "found", tree_count, "trees")
    return tree_count