#abc252h. [abc252_h]K-th beautiful Necklace

[abc252_h]K-th beautiful Necklace

Problem Statement

We have NN gemstones. The color and beauty of the ii-th gemstone are DiD_i and ViV_i, respectively.
Here, the color of each gemstone is one of 1,2,ldots,C1, 2, \\ldots, C, and there is at least one gemstone of each color.

Out of the NN gemstones, we will choose CC with distinct colors and use them to make a necklace. (The order does not matter.) The beautifulness of the necklace will be the bitwise rmXOR\\rm XOR of the chosen gemstones.

Among all possible ways to make a necklace, find the beautifulness of the necklace made in the way with the KK-th greatest beautifulness. (If there are multiple ways with the same beautifulness, we count all of them.)

What is bitwise rmXOR\\rm XOR?

The bitwise rmXOR\\rm XOR of integers AA and BB, AoplusBA \\oplus B, is defined as follows:

  • When AoplusBA \\oplus B is written in base two, the digit in the 2k2^k's place (kgeq0k \\geq 0) is 11 if either AA or BB, but not both, has 11 in the 2k2^k's place, and 00 otherwise.

For example, 3oplus5=63 \\oplus 5 = 6. (In base two: 011oplus101=110011 \\oplus 101 = 110.)

Constraints

  • 1leqCleqNleq701 \\leq C \\leq N \\leq 70
  • 1leqDileqC1 \\leq D_i \\leq C
  • 0leqVi<2600 \\leq V_i < 2^{60}
  • 1leqKleq10181 \\leq K \\leq 10^{18}
  • There are at least KK ways to make a necklace.
  • All values in input are integers.

Input

Input is given from Standard Input in the following format:

NN CC KK D1D_1 V1V_1 vdots\\vdots DND_N VNV_N

Output

Print the answer.


Sample Input 1

4 2 3
2 4
2 6
1 2
1 3

Sample Output 1

5

There are four ways to make a necklace, as follows.

  • Choose the 11-st and 33-rd gemstones to make a necklace with the beautifulness of 4rmXOR2=64\\ {\\rm XOR}\\ 2 =6.
  • Choose the 11-st and 44-th gemstones to make a necklace with the beautifulness of 4rmXOR3=74\\ {\\rm XOR}\\ 3 =7.
  • Choose the 22-nd and 33-rd gemstones to make a necklace with the beautifulness of 6rmXOR2=46\\ {\\rm XOR}\\ 2 =4.
  • Choose the 22-nd and 44-th gemstones to make a necklace with the beautifulness of 6rmXOR3=56\\ {\\rm XOR}\\ 3 =5.

Thus, the necklace with the 33-rd greatest beautifulness has the beautifulness of 55.


Sample Input 2

3 1 2
1 0
1 0
1 0

Sample Output 2

0

There are three ways to make a necklace, all of which result in the beautifulness of 00.


Sample Input 3

10 3 11
1 414213562373095048
1 732050807568877293
2 236067977499789696
2 449489742783178098
2 645751311064590590
2 828427124746190097
3 162277660168379331
3 316624790355399849
3 464101615137754587
3 605551275463989293

Sample Output 3

766842905529259824