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Problems

Cow Land

Cow Land

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. Certain pairs of attractions are connected by pathways, n1 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 ei, 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.

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

Input

The first line contains n (2n105) and a number of queries q (1q105). The next line contains e1...en (0ei109). The next n1 lines each describe a pathway in terms of two integer attraction IDs a and b (both in the range 1...n). Finally, the last q lines each describe either an update to one of the ei values or a query for the enjoyment of a route. A line of the form "1 i v" indicates that ei should be updated to value v, and a line of the form "2 i j" is a query for the enjoyment of the route connecting attractions i and j.

Output

For each query of the form "2 i j", print on a single line the enjoyment of the route from i to j.

Time limit 1 second
Memory limit 128 MiB
Input example #1
5 5
1 2 4 8 16
1 2
1 3
3 4
3 5
2 1 5
1 1 16
2 3 5
2 1 5
2 1 3
Output example #1
21
20
4
20
Source 2019 USACO February, Gold