#include <iostream>
using namespace std;
int main(){
  long long n,l;cin>>n>>l;
  long long prev = 0;
  long long nw = 0;
  for(int i = 0; n > i; i++){
    long long x,w,t;cin>>x>>w>>t;
    nw += x-prev;
    if(t-w < nw%(2*t))nw += 2*t-(nw%(2*t));
    nw += w;
    prev = x+w;
  }
  cout << nw+l-prev << endl;
}