Here are jokes with statuses, such as we go in order along the vertices and if we get to a vertex that we haven't been to, then we start going in a cycle from this vertex, setting the status of this cycle, if we get to the same status, then this is a cycle, if we get to a vertex with a lower status, then everything is fine and we stop the cycle, and if the vertex has no status, then we just opened a new vertex and it turns out that the algorithm is linear