#include<stdio.h>
#include<queue>
#include<vector>
#include<fstream>
#include<algorithm>
using namespace std;

#define ll long long

ifstream f("gardieni.in");
ofstream g("gardieni.out");

#define MaxN 50010
#define Max11 15
#define MaxT 1000100

int N,T,nr;
ll MAX,B[MaxT];
/*ll MAX;
gard A[MaxN];

struct comp{
    bool operator () (const int &a, const int &b){
        if(A[a].a == A[b].a)
			return A[a].b > A[b].b;
		return A[a].a > A[b].a;
    }
};

priority_queue<int, vector<int>,comp> Q;
//Varianta cu cozi de prioritate

void citire(void)
{
	f >> N >> T;
	for(int i=1;i<=N;i++)
	{
		f >> A[i].a >> A[i].b >> A[i].c;
		Q.push(i);
	}
}

inline int cmp(int a,int b)
{
	return A[a].c < A[b].c;
}*/

inline ll min(ll a,ll b)
{
	return a < b ? a : b;
}

/*void TimpMinim(void)
{
	int Max;
	
	for(;!Q.empty();)
	{
		nr = 1;
		B[nr] = Q.top(); Q.pop();
		
		for(;!Q.empty() && A[Q.top()].a == A[B[nr]].a;B[++nr] = Q.top(),Q.pop());
		
		sort(B+1,B+nr+1,cmp);
		
		!Q.empty() ? Max = min(A[Q.top()].a-1,A[B[1]].b) : Max = A[B[1]].b;
		
		MAX += (Max-A[B[1]].a+1)*A[B[1]].c;
		
		for(int i=1;i<=nr;i++)
			if(Max < A[B[i]].b)
			{
				A[B[i]].a = Max+1;
				Q.push(B[i]);
			}
	}
}*/

int main()
{
	int a,b;
	ll c;
	
	f >> N >> T;
	
	for(int i=1;i<=T;i++)
		B[i] = 10000000*10000*1000*1LL;
	
	for(int i=1;i<=N;i++)
	{
		f >> a >> b >> c;
		for(int j=a;j<=b;j++)
			B[j] = min(B[j],c);
	}
	
	for(int i=1;i<=T;i++)
		MAX += B[i];
	
	g << MAX;
	
	return 0;
}