#include <bits/stdc++.h>
using namespace std;
const int maxN = 3e5 + 5;
int n, D;
int x[maxN], a[maxN], b[maxN];
pair<int, int> des[maxN];
vector<int> val, place;
struct node {
long long val, lazy;
} st[4 * maxN];
void down(int id) {
long long t = st[id].lazy;
st[2 * id].val += t;
st[2 * id + 1].val += t;
st[2 * id].lazy += t;
st[2 * id + 1].lazy += t;
st[id].lazy = 0;
}
void build(int id, int l, int r) {
if (l == r) {
st[id].val = place[l - 1];
return ;
}
int mid = (l + r) >> 1;
build(2 * id, l, mid);
build(2 * id + 1, mid + 1, r);
st[id].val = max(st[2 * id].val, st[2 * id + 1].val);
}
void update(int id, int l, int r, int u, int v, int val) {
if (v < l || r < u) return ;
if (u <= l && r <= v) {
st[id].lazy += val;
st[id].val += val;
return ;
}
int mid = (l + r) >> 1;
down(id);
update(2 * id, l, mid, u, v, val);
update(2 * id + 1, mid + 1, r, u, v, val);
st[id].val = max(st[2 * id].val, st[2 * id + 1].val);
}
long long get(int id, int l, int r, int pos) {
if (l == r) return st[id].val;
int mid = (l + r) >> 1;
down(id);
if (pos <= mid) return get(2 * id, l, mid, pos);
return get(2 * id + 1, mid + 1, r, pos);
}
vector<pair<int, int>> query;
long long find_ans(int res) {
long long mn = 1e18, sum = res;
for (int i = 1; i <= n; i++)
if (res <= b[i]) query.push_back({x[i], a[i]});
sort(query.begin(), query.end());
int pre = 0;
for (auto it: query) {
sum = sum - (it.first - pre);
mn = min(mn, sum);
sum = sum + it.second;
pre = it.first;
}
return res - mn;
}
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> D;
for (int i = 1; i <= n; i++)
cin >> x[i] >> a[i] >> b[i];
n++;
x[n] = D; a[n] = 0; b[n] = D;
for (int i = 1; i <= n; i++) {
des[i] = {b[i], i};
place.push_back(x[i]);
val.push_back(b[i]);
}
sort(des + 1, des + n + 1);
sort(val.begin(), val.end());
val.erase(unique(val.begin(), val.end()), val.end());
sort(place.begin(), place.end());
place.erase(unique(place.begin(), place.end()), place.end());
int m = place.size();
build(1, 1, m);
for (int i = 1; i <= n; i++) {
int pos = lower_bound(place.begin(), place.end(), x[i]) - place.begin() + 1;
update(1, 1, m, pos + 1, m, -a[i]);
}
if (st[1].val <= val[0]) {
cout << find_ans(val[0]);
return 0;
}
int id = 1;
for (int i = 1; i < val.size(); i++) {
int v = val[i - 1];
while (des[id].first == v) {
int i = des[id].second;
int pos = lower_bound(place.begin(), place.end(), x[i]) - place.begin() + 1;
update(1, 1, m, pos + 1, m, a[i]);
id++;
}
if (st[1].val <= val[i]) {
cout << find_ans(val[i]);
return 0;
}
}
return 0;
}
