#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
#define rep(i, n) REP(i, 0, n)
#define REP(i, s, e) for (ll i = (s); i < (ll)(e); i++)
#define repr(i, n) REPR(i, n, 0)
#define REPR(i, s, e) for (ll i = (ll)(s - 1); i >= (ll)(e); i--)
#define all(r) r.begin(), r.end()
#define rall(r) r.rbegin(), r.rend()

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;

template <typename T, typename U>
T chmax(T& a, const U& b) {
    if (a >= b) return false;
    a = b;
    return true;
}
template <typename T, typename U>
T chmin(T& a, const U& b) {
    if (a <= b) return false;
    a = b;
    return true;
}

void yes_no(bool f, string yes = "Yes", string no = "No") { cout << (f ? yes : no) << "\n"; }

vector<string> split_string(const string& s, char c = ' ') {
    vector<string> res;
    stringstream ss(s);
    string tmp;
    while (getline(ss, tmp, c)) {
        res.emplace_back(tmp);
    }
    return res;
}

void solve() {
    ll n, l;
    cin >> n >> l;
    ll ans = 0;
    ll cur = 0;
    rep(i, n) {
        ll x, w, t;
        cin >> x >> w >> t;
        ans += x - cur;
        ll a = ans % (2 * t);
        if (a + w <= t) {
            ans += w;
        } else {
            ans += 2 * t - a + w;
        }
        cur = x + w;
    }
    ans += l - cur;
    cout << ans << "\n";
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int t = 1;
    // multi-testcase
    // cin >> t;
    rep(ti, t) solve();
    return 0;
}