atcoder#ABC254C. [ABC254C] K Swap

[ABC254C] K Swap

Score : 300300 points

Problem Statement

We have a sequence of length NN: A=(a1,,aN)A=(a_1,\ldots,a_N). Additionally, you are given an integer KK.

You can perform the following operation zero or more times.

  • Choose an integer ii such that 1iNK1 \leq i \leq N-K, then swap the values of aia_i and ai+Ka_{i+K}.

Determine whether it is possible to sort AA in ascending order.

Constraints

  • 2N2×1052 \leq N \leq 2 \times 10^5
  • 1KN11 \leq K \leq N-1
  • 1ai1091 \leq a_i \leq 10^9
  • All values in input are integers.

Input

Input is given from Standard Input in the following format:

NN KK

a1a_1 \ldots aNa_N

Output

If it is possible to sort AA in ascending order, print Yes; otherwise, print No.

5 2
3 4 1 3 4
Yes

The following sequence of operations sorts AA in ascending order.

  • Choose i=1i=1 to swap the values of a1a_1 and a3a_3. AA is now (1,4,3,3,4)(1,4,3,3,4).
  • Choose i=2i=2 to swap the values of a2a_2 and a4a_4. AA is now (1,3,3,4,4)(1,3,3,4,4).
5 3
3 4 1 3 4
No
7 5
1 2 3 4 5 5 10
Yes

No operations may be needed.