#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int long long
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FORD(i, a, b) for (int i = (b); i >= (a); i --)
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPD(i, n) for (int i = (n) - 1; i >= 0; --i)
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
/*
Phu Trong from Nguyen Tat Thanh High School for gifted student
*/
template <class X, class Y>
bool minimize(X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
int N, K;
#define MAX 300005
struct Event{
int X, A, B;
Event(){}
Event(int _X, int _A, int _B): X(_X), A(_A), B(_B){}
bool operator < (const Event& oth) const{
return B > oth.B;
}
} A[MAX];
template <class T = vector<int>>
T unique(T v){
sort(v.begin(), v.end());
v.resize(unique(v.begin(), v.end()) - v.begin());
return v;
}
template <class T = int>
T find(T x, const vector<T>& v){
return upper_bound(v.begin(), v.end(), x) - v.begin();
}
template <class T = int> struct SegmentTree{
int n;
vector<T> st, lz;
SegmentTree(int _n){
this -> n = _n;
st.resize((n << 2) + 5);
lz.resize((n << 2) + 5);
}
void pushDown(int id){
if (!lz[id]) return;
st[id << 1] += lz[id];
st[id << 1 | 1] += lz[id];
lz[id << 1] += lz[id];
lz[id << 1 | 1] += lz[id];
lz[id] = 0;
}
void upd(int id, int l, int r, int u, int v, T val){
if (u > r || v < l) return;
if (u <= l && v >= r){
st[id] += val; lz[id] += val;
return;
}
int m = (l + r) >> 1;
pushDown(id);
upd(id << 1, l, m, u, v, val);
upd(id << 1 | 1, m + 1, r, u, v, val);
st[id] = min(st[id << 1], st[id << 1 | 1]);
}
void upd(int l, int r, T val){
upd(1, 0, n, l, r, val);
}
};
void process(void){
cin >> N >> K;
vector<Event> event;
vector<int> pos;
for (int i = 1; i <= N; ++i){
int x, a, b; cin >> x >> a >> b;
event.push_back(Event(x, a, b));
pos.push_back(x);
}
event.push_back(Event(K, 0, 0));
pos.push_back(0); pos.push_back(K);
pos = unique(pos);
N = (int)pos.size();
SegmentTree<int> st(N);
for (int i = 0; i < N; ++i){
st.upd(i, i, -pos[i]);
}
sort(event.begin(), event.end());
int ans = K;
for (auto&x : event){
int p = find(x.X, pos);
st.upd(p, N, x.A);
//Let's assume F <= x.B
if (abs(st.st[1]) <= x.B){
//if F is satisfied we update the answer
minimize(ans, abs(st.st[1]));
}
}
cout << ans;
}
signed main(){
#define name "Whisper"
cin.tie(nullptr) -> sync_with_stdio(false);
//freopen(name".inp", "r", stdin);
//freopen(name".out", "w", stdout);
process();
}
