#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <string>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <iomanip>
using ll = long long;
using uint = unsigned int;
using graph = std::vector<std::vector<ll>>;
using wGraph = std::vector<std::vector<std::pair<ll,ll>>>;
#define rep(i,n) for (int i=0; i < int(n); i++)

using namespace std;
ll MOD7 = 1000000007;
ll MOD9 = 1000000009;
vector<ll> InputVec(ll N){
    vector<ll> A(N);
    for (int i = 0; i < N; ++i) {
        cin >> A[i];
    }
    return A;
}
void OutputVec(vector<ll> A){
    for (int i = 0; i < A.size(); ++i) {
        cout << A[i] << ",";
    }
    cout << endl;
}
vector<vector<ll>> InputVec2d(ll H,ll W){
    vector<vector<ll>> A(H);
    for (int yi = 0; yi < H; ++yi) {
        A[yi] = vector<ll>(W);
    }
    for (int yi = 0; yi < H; ++yi) {
        for (int xi = 0; xi < W; ++xi) {
            cin >> A[yi][xi];
        }
    }
    return A;
}
vector<vector<char>> InputVec2dStr(ll H,ll W){
    vector<vector<char>> A(H);
    for (int yi = 0; yi < H; ++yi) {
        A[yi] = vector<char>(W);
    }
    for (int yi = 0; yi < H; ++yi) {
        string S;
        cin >> S;
        for (int xi = 0; xi < W; ++xi) {
            A[yi][xi] = S[xi];
        }
    }
    return A;
}
void OutputVec2d(vector<vector<ll>> A){
    for (int yi = 0; yi < A.size(); ++yi) {
        for (int xi = 0; xi < A[yi].size(); ++xi) {
            cout << A[yi][xi] << ",";
        }
        cout << endl;
    }
}
graph InputGraph(ll N,ll M){
    graph G(N);
    for (int i = 0; i < M; ++i) {
        ll a,b;
        cin >> a >> b;
        a--;b--;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    return G;
}
graph InputDGraph(ll N,ll M){
    graph G(N);
    for (int i = 0; i < M; ++i) {
        ll a,b;
        cin >> a >> b;
        a--;b--;
        G[a].push_back(b);
    }
    return G;
}
wGraph InputWGraph(ll N,ll M){
    wGraph G(N);
    for (int i = 0; i < M; ++i) {
        ll a,b,c;
        cin >> a >> b >> c;
        a--;b--;
        G[a].push_back(make_pair(b,c));
        G[b].push_back(make_pair(a,c));
    }
    return G;
}
wGraph InputDWGraph(ll N, ll M){
    wGraph G(N);
    for (int i = 0; i < M; ++i) {
        ll a,b,c;
        cin >> a >> b >> c;
        a--;b--;
        G[a].push_back(make_pair(b,c));
    }
    return G;
}
void OutputGraph(graph G){
    for (int i = 0; i < G.size(); ++i) {
        cout << i << ":";
        for (int j = 0; j < G[i].size(); ++j) {
            cout << G[i][j]<< ",";
        }
        cout << endl;
    }
}

void OutputGraph(wGraph G){
    for (int i = 0; i < G.size(); ++i) {
        cout << i << ":";
        for (int j = 0; j < G[i].size(); ++j) {
            cout << G[i][j].first <<"/" << G[i][j].second << ",";
        }
        cout << endl;
    }
}

void OutputAnswerBool(bool b,bool isUpperCase = false){
    if(b){
        if(isUpperCase){
            cout << "YES" << endl;
        }else{
            cout << "Yes" << endl;
        }
    }else{
        if(isUpperCase){
            cout << "NO" << endl;
        }else{
            cout << "No" << endl;
        }
    }
}

int main() {
    ll N, K;
    cin >> N >> K;
    vector<vector<ll>> memoB(K+1);
    vector<vector<ll>> memoW(K+1);
    vector<vector<ll>> orderB(K);
    vector<vector<ll>> orderW(K);
    for (int yi = 0; yi <= K; ++yi) {
        memoB[yi] = vector<ll>(K+1);
        memoW[yi] = vector<ll>(K+1);
        if(yi == K){
            continue;
        }
        orderB[yi] = vector<ll>(K);
        orderW[yi] = vector<ll>(K);
    }
    for (int i = 0; i < N; ++i) {
        ll x,y;
        cin >> x >> y;
        char c;
        cin >> c;
        ll color = 0;
        if(c == 'W'){
            color = 1;
        }
        color += x/K + y/K;
        if(color % 2 == 0){
            orderB[y % K][x % K]++;
        }else{
            orderW[y % K][x % K]++;
        }
    }
    for (int yi = 1; yi <= K; ++yi) {
        for (int xi = 1; xi <= K; ++xi) {
                memoB[yi][xi]  = memoB[yi-1][xi] + memoB[yi][xi-1] - memoB[yi-1][xi-1] + orderB[yi-1][xi-1];
                memoW[yi][xi]  = memoW[yi-1][xi] + memoW[yi][xi-1] - memoW[yi-1][xi-1] + orderW[yi-1][xi-1];
        }
    }
    ll res = 0;
    for (int yi = 0; yi < K; ++yi) {
        for (int xi = 0; xi < K; ++xi) {
            ll b = memoB[K][K] - memoB[yi][K] - memoB[K][xi] + 2 * memoB[yi][xi];
            b += memoW[yi][K] + memoW[K][xi] - 2 * memoW[yi][xi];
            ll w = memoW[K][K] - memoW[yi][K] - memoW[K][xi] + 2 * memoW[yi][xi];
            w += memoB[yi][K] + memoB[K][xi] - 2 * memoB[yi][xi];
            res = max(res,max(b,w));
        }
    }
    cout << res << endl;
    
}

Measured memory_bytes: 31616