typedef long long ll;
typedef long double ld;

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

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<typename T>
using ordered_set = tree<T, null_type, std::less<T>, rb_tree_tag, tree_order_statistics_node_update>;
// std::cout << *s.find_by_order(1) << std::endl; // 2

signed main(){
    // これがないと落ちることがある
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    ll n,l;
    cin >> n>>l;
    ll cnt = 0;
    ll now = 0;

    for (ll i = 0; i < n; i++){
        ll x,w,t;
        cin >> x>>w>>t;
        cnt += x-now;
        now = x;
        auto c = cnt%(2*t);
        if(w+c<=t){
            cnt+=w;
            now=x+w;
        }else{
            cnt+=2*t-c+w;
            now=x+w;
        }
    }
    cout << cnt+l-now << endl;
}