Roads#2203
The mayor of Gadyukino decided to check the condition of the roads after a recent major repair. To do this, he wants to travel along every road in both directions.
Help the mayor plan the shortest route that passes through each road in both directions at least once.
The city of Gadyukino has intersections and roads. Each road connects two different intersections. There is no more than one road between any two intersections.
It is known that it is possible to reach any intersection from any other using the roads.
The input file contains integers and (1 \leq n \leq 10^4, 1 \leq m \leq 10^5), followed by pairs of integers a_i and b_i — the numbers of the intersections connected by the -th road.
Output the number — the minimum route length, followed by s+1 integers — the sequence of intersection numbers showing the order in which they should be visited.
Example 1