static void Main()
{
var ss = new StreamScanner(new StreamReader(Console.OpenStandardInput()));
var sw = new StreamWriter(Console.OpenStandardOutput())
{
AutoFlush = false
};
new Program().Solve(ss, sw);
sw.Flush();
}
void Solve(StreamScanner ss, StreamWriter sw)
{
//---------------------------------
N = ss.Next(int.Parse);
K = ss.Next(int.Parse);
K2 = K * 2;
imos = new int[K2 + 1, K2 + 1];
for (var i = 0; i < N; i++)
{
var X = ss.Next(int.Parse);
var Y = ss.Next(int.Parse);
var C = ss.Next(String);
if (C == "B")
{
X += K;
}
Add(X, Y, X + K - 1, Y + K - 1);
Add(X + K, Y + K, X + K2 - 1, Y + K2 - 1);
}
for (var i = 0; i <= 2 * K; i++)
{
for (var j = 0; j <= 2 * K; j++)
{
if (i != 0)
{
imos[i, j] += imos[i - 1, j];
}
if (j != 0)
{
imos[i, j] += imos[i, j - 1];
}
if (i != 0 && j != 0)
{
imos[i, j] -= imos[i - 1, j - 1];
}
}
}
var max = 0;
foreach (var value in imos)
{
max = Math.Max(max, value);
}
sw.WriteLine(max);
//---------------------------------
}
