#include <iostream>
using namespace std;
int main(){
	int n,l;	cin>>n>>l;
	int now=0,time=0;
	int x,w,t;
	for(int i=0;i<n;i++){
		cin>>x>>w>>t;
		time+=(x-now);
		now=x;
		int next=(time/(2*t))*2*t;
		if(next+t<time+w)	time=next+2*t;
	}
	time+=(l-now);
	cout<<time<<endl;
	return 0;
}