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 PYTHON3):

Solution:
import sys
input = sys.stdin.readline
INF = float("inf")


class Acc2D:
    def __init__(self, grid):
        self.h, self.w = len(grid), len(grid[0])
        self.acc2D = self._build(self.h, self.w, grid)

    def _build(self, h, w, grid):
        ret = [[0] * (w + 1) for _ in range(h + 1)]
        for r in range(h):
            for c in range(w):
                ret[r + 1][c + 1] = ret[r][c + 1] + ret[r + 1][c] - ret[r][c] + grid[r][c]
        return ret

    def get(self, r1, r2, c1, c2):
        if r1 < 0:
            r1 = 0
        if r2 >= self.h:
            r2 = self.h
        if c1 < 0:
            c1 = 0
        if c2 >= self.w:
            c2 = self.w
        cnt = self.acc2D
        return cnt[r2][c2] - cnt[r1][c2] - cnt[r2][c1] + cnt[r1][c1]


def main():
    n, k = map(int, input().split())
    g = [[0] * (2 * k) for _ in range(2 * k)]
    for _ in range(n):
        x, y, c = input().split()
        x = int(x) % (2 * k)
        y = int(y) % (2 * k)
        if c == 'B':
            y = (y + k) % (2 * k)
        g[y][x] += 1
    acc2d = Acc2D(g)
    ans = 0
    for r in range(k):
        for c in range(k):
            tmp = acc2d.get(0, r, 0, c)
            tmp += acc2d.get(0, r, c + k, c + k * 2)
            tmp += acc2d.get(r, r + k, c, c + k)
            tmp += acc2d.get(r + k, r + k * 2, 0, c)
            tmp += acc2d.get(r + k, r + k * 2, c + k, c + k * 2)
            ans = max(ans, tmp, n - tmp)
    print(ans)


if __name__ == '__main__':
    main()