#include<stdio.h>
#include<vector>
#include<algorithm>
#define cost first
#define from second.first
#define to second.second
using namespace std;
FILE*in=fopen("gardieni.in","r");
FILE*out=fopen("gardieni.out","w");
int n,t,y,v[1000001],contor,suma;
pair <int, pair<int,int> > a[50006];
int main()
{
	fscanf(in,"%d%d",&n,&t);
	for(int ii=1;ii<=n;++ii)
	{	
		int data1,data2,data3;
		fscanf(in,"%d%d%d",&data1,&data2,&data3);
		a[ii].cost=data3;
		a[ii].from=data1;
		a[ii].to=data2;
	}
	sort(a+1,a+n+1);
	contor=1;
	while(t)
	{
		for(int i=a[contor].from;i<=a[contor].to;++i)
		{
			if(!v[i])
			{
				v[i]=a[contor].cost;
				--t;
				suma+=v[i];
			}
		}
		contor++;
	}

	fprintf(out,"%d",suma);

	fclose(in);
	fclose(out);
return 0;	
}