Problem: AtCoDeer is thinking of painting an infinite two-dimensional grid in a checked pattern of side K. Here, a checked pattern of side K is a pattern where each square is painted black or white so that each connected component of each color is a K × K square. Below is an example of a checked pattern of side 3:

cba927b2484fad94fb5ff7473e9aadef.png

AtCoDeer has N desires. The i-th desire is represented by x_i, y_i and c_i. If c_i is `B`, it means that he wants to paint the square (x_i,y_i) black; if c_i is `W`, he wants to paint the square (x_i,y_i) white. At most how many desires can he satisfy at the same time?

Constraints

* 1 ≤ N ≤ 10^5
* 1 ≤ K ≤ 1000
* 0 ≤ x_i ≤ 10^9
* 0 ≤ y_i ≤ 10^9
* If i ≠ j, then (x_i,y_i) ≠ (x_j,y_j).
* c_i is `B` or `W`.
* N, K, x_i and y_i are integers.

Input

Input is given from Standard Input in the following format:


N K
x_1 y_1 c_1
x_2 y_2 c_2
:
x_N y_N c_N


Output

Print the maximum number of desires that can be satisfied at the same time.

Examples

Input

4 3
0 1 W
1 2 W
5 3 B
5 4 B


Output

4


Input

2 1000
0 0 B
0 1 W


Output

2


Input

6 2
1 2 B
2 1 W
2 2 B
1 0 B
0 6 W
4 5 W


Output

4

Solution (in PYTHON):

Solution:
#!/usr/bin/env python

from collections import deque
import itertools as it
import sys
import math

sys.setrecursionlimit(1000000)

R,r=range,raw_input
N,K=map(int,r().split())
L=K+1
P,Q=R(K),R(L)
D=[L*[0]for i in Q]
a=b=0
for i in R(N):
 x,y,c=r().split()
 x,y=int(x),int(y)
 p=(x/K+y/K+ord(c))%2
 D[y%K+1][x%K+1]+=1-2*p
 b+=p
for i in P:
 for j in Q:D[i+1][j]+=D[i][j]
for i in P:
 for j in Q:D[j][i+1]+=D[j][i]
for i in Q:
 for j in Q:
  S=D[i][K]+D[K][j]-D[i][j]*2
  a=max(a,S,D[K][K]-S)
print a+b