atcoder#ABC257H. [ABC257Ex] Dice Sum 2

[ABC257Ex] Dice Sum 2

Score : 600600 points

Problem Statement

The six-sided dice speciality shop "Saikoroya" sells NN dice. The ii-th die (singular of dice) has Ai,1,Ai,2,,Ai,6A_{i,1},A_{i,2},\ldots,A_{i,6} written on its each side, and has a price of CiC_i.

Takahashi is going to choose exactly KK of them and buy them.

Currently, "Saikoroya" is conducting a promotion: Takahashi may roll each of the purchased dice once and claim money whose amount is equal to the square of the sum of the numbers shown by the dice. Here, each die shows one of the six numbers uniformly at random and independently.

Maximize the expected value of (the amount of money he claims) - (the sum of money he pays for the purchased KK dice) by properly choosing KK dice to buy. Print the maximized expected value modulo 998244353998244353.

Definition of the expected value modulo $998244353$

We can prove that the sought expected value is always a rational number. Moreover, under the Constraints of this problem, the sought expected value can be expressed by an irreducible fraction yx\frac{y}{x} where xx is indivisible by 998244353998244353.

In this case, we can uniquely determine the integer zz between 00 and 998244352998244352 (inclusive) such that xzy(mod998244353)xz \equiv y \pmod{998244353}. Print such zz.

Constraints

  • 1N10001 \leq N \leq 1000
  • 1KN1 \leq K \leq N
  • 1Ci1051 \leq C_i \leq 10^5
  • 1Ai,j1051 \leq A_{i,j} \leq 10^5
  • All values in input are integers.

Input

Input is given from Standard Input in the following format:

NN KK

C1C_1 C2C_2 \ldots CNC_N

A1,1A_{1,1} A1,2A_{1,2} \ldots A1,6A_{1,6}

\vdots

AN,1A_{N,1} AN,2A_{N,2} \ldots AN,6A_{N,6}

Output

Print the answer.

3 2
1 2 3
1 1 1 1 1 1
2 2 2 2 2 2
3 3 3 3 3 3
20

If he buys the 22-nd and 33-rd dice, the expected value of (the amount of money he claims) - (the sum of money he pays for the purchased KK dice) equals (2+3)2(2+3)=20(2 + 3)^2 - (2 + 3) = 20, which is the maximum expected value.

10 5
2 5 6 5 2 1 7 9 7 2
5 5 2 4 7 6
2 2 8 7 7 9
8 1 9 6 10 8
8 6 10 3 3 9
1 10 5 8 1 10
7 8 4 8 6 5
1 10 2 5 1 7
7 4 1 4 5 4
5 10 1 5 1 2
5 1 2 3 6 2
1014