#include <fstream>
#include <cstring>
#include <algorithm>
#define DIM 3505
#define x first
#define y second.first
#define z second.second
#define lsb(a) ((a)^((a)-1))&(a)
using namespace std;
#include <stdio.h>
#include <ctype.h>
FILE *_fin;
int _in_loc; char _in_buff[4096];
 
 
void read_init(const char* nume)
{
	_fin = fopen(nume, "r");
	_in_loc = 4095;
}
 
char read_ch()
{
	++_in_loc;
	if (_in_loc == 4096) {
		_in_loc = 0;
		fread(_in_buff, 1, 4096, _fin);
	}
	return _in_buff[_in_loc];
}
 
int read_u32()
{
	int u32 = 0; char c;
	while (!isdigit(c = read_ch()) && c != '-');
	int sgn = 1;
	if (c == '-') {
		sgn = -1;
	} else {
		u32 = c - '0';
	}
	while (isdigit(c = read_ch())) {
		u32 = u32 * 10 + c - '0';
	}
	return u32 * sgn;
}
 
ofstream fo("cutii.out");
int T;
int n;
pair<int,pair<int,int> > p[DIM];
short int AIB[DIM][DIM];
char last[DIM][DIM];
void update(int a,int b,short int val,char test)
{
	for(int i=a;i<=n;i+=lsb(i))
		for(int j=b;j<=n;j+=lsb(j))
			if(last[i][j]==test)
				AIB[i][j]=max(AIB[i][j],val);
			else
				AIB[i][j]=val,last[i][j]=test;
}
short int query(int a,int b,char test)
{
	short int rez=0;
	for(int i=a;i>0;i-=lsb(i))
		for(int j=b;j>0;j-=lsb(j))
			if(last[i][j]==test)
				rez=max(rez,AIB[i][j]);
	return rez;
}
int main()
{
	read_init("cutii.in");
	n=read_u32(),T=read_u32();
	for(int t=0;t<T;t++)
	{
		for(int i=1;i<=n;i++)
			p[i].x=read_u32(),p[i].y=read_u32(),p[i].z=read_u32();
		sort(p+1,p+n+1);
		for(int i=1;i<=n;i++)
			update(p[i].y,p[i].z,query(p[i].y-1,p[i].z-1,t)+1,t);
		fo<<query(n,n,t)<<"\n";
	}
	fo.close();
	return 0;
}