#include<bits/stdc++.h>
using namespace std;


int main(){
	int N,L;
	cin >> N >> L;
	int pos=0;
	int time=0;
	for(int i=0;i<N;i++){
		int x,w,t;
		cin >> x >> w >> t;
		time+=x-pos;
		pos=x;
		
		int time2=(time/(2*t))*2*t;
		if(time2+t<time+w) time=time2+2*t;
	}
	time+=L-pos;
	cout << time << endl;
	return 0;
}