Cow Land is a special amusement park for cows, where they roam around, eat delicious grass, and visit different cow attractions (the roller cowster is particularly popular).

There are a total of N different attractions (2 \leq N \leq 10^5). Certain pairs of attractions are connected by pathways, N-1 in total, in such a way that there is a unique route consisting of various pathways between any two attractions. Each attraction i has an integer enjoyment value e_i, which can change over the course of a day, since some attractions are more appealing in the morning and others later in the afternoon.

A cow that travels from attraction i to attraction j gets to experience all the attractions on the route from i to j. Curiously, the total enjoyment value of this entire route is given by the bitwise XOR of all the enjoyment values along the route, including those of attractions i and j.

Please help the cows determine the enjoyment values of the routes they plan to use during their next trip to Cow Land.

Problem credits: Charles Bailey

#4108 upload 8 done 3 how_to_reg 3

Cow Land timer 2s memory 512MB

#4108

Cow Land 2s 512MB