#include<stdio.h>
#include<algorithm>


struct sirstr{
       int x,y,z,ev;
       };
       
int main()
{
 int n ,t;
 sirstr sir[3500];
 int max=0;
 int var;
 int c,d;
 int c3;
 freopen("cutii.in","r",stdin);
 freopen("cutii.out","w",stdout);
 
 scanf("%d%d", &n, &t);


 for (int c1 = 1; c1 <= n; c1++)
 {
   scanf("%d%d%d", &sir[c1].x, &sir[c1].y, &sir[c1].z);  
}
c = 1;

for (int c1 = 1; c1 <= n; c1++)
{
if (sir[c1].x < sir[c1].x)
{
sir[0] = sir[1];
sir[1] = sir[2];
sir[2] = sir[0];
}
sir[c1].ev = 1;
}
  
for (c=1; c<= n; c++)
{
    for (d=1; d<=n-c+1;d++)
    {
  if ((sir[c].y < sir[c+d].y) && (sir[c].z < sir[c+d].z) && (sir[c].ev < sir[c+d].ev))
  sir[c+d].ev = sir[c+d].ev + 1;
}
  
  
}
  
  for (c3 = 1; c3<= n;c3++)
  {
  if (sir[c3].ev >= max)
  max = sir[c3].ev;
}

  printf("%d\n", max+1);

}