#include<bits/stdc++.h>
using namespace std;
const int MAXN = 3e5;
struct station {
int x, f, r;
};
vector <station> stations,order;
long long int initial[MAXN+1],diff[MAXN+1];
struct node {
long long int min1;
long long int sum;
node operator+ (node& other) {
return {min(min1+other.sum,other.min1), sum+other.sum};
}
};
node tree[4*(MAXN+1)];
void build_tree(int ind, int l, int r) {
if (l == r) {
tree[ind] = {diff[l], diff[l]};
return ;
}
int mid = (l + r) >> 1;
build_tree(2*ind + 1, l, mid);
build_tree(2*ind + 2, mid + 1, r);
tree[ind] = tree[2*ind + 1] + tree[2*ind + 2];
}
void update(int ind, int l, int r, int pos, int val) {
if (l == r) {
tree[ind].min1 += val;
tree[ind].sum += val;
sreturn ;
}
int mid = (l + r) >> 1;
if (pos<=mid) update(2*ind + 1, l, mid, pos, val);
else update(2*ind + 2, mid + 1, r, pos, val);
tree[ind] = tree[2*ind + 1] + tree[2*ind + 2];
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n,l;
cin >> n >> l ;
stations.resize(n);
for (auto& [x, f, r] : stations) {
cin >> x >> f >> r ;
}
stations.push_back({l, 0, (int)1e9});
n++;
sort(stations.begin(), stations.end(), [](station& s1, station& s2) {
return (s1.x < s2.x) || ((s1.x == s2.x) && (s1.r < s2.r));
});
long long int sumf=0;
for (int i=0; i<n; i++) {
auto [x, f, r]=stations[i];
initial[i]=sumf-x;
sumf+=f;
}
diff[n-1]=initial[n-1];
for (int i=n-2; i>=0; i--) {
diff[i]=initial[i]-initial[i+1];
}
build_tree(0,0,n-1);
order.reserve(n);
for (int i=0; i<n; i++) {
auto [x, f, r]=stations[i];
order.push_back({i, f, r});
}
sort(order.begin(),order.end(),[] (station& s1, station& s2){
return (s1.r < s2.r);
});
int prv = 0;
for (int i = 0; i < n; i++) {
update(0, 0, n-1, n-1, order[i].r - prv);
prv = order[i].r;
if (tree[0].min1 >= 0) {
cout << order[i].r - tree[0].min1;
break;
}
for (int j = i; j < n; j++) {
auto [x, f, r] = order[j];
if (r != order[i].r) {
i = j - 1;
break;
}
if (x != n-1) {
update(0, 0, n-1, n-1, -f);
update(0, 0, n-1, x, f);
}
if (j == n-1) i = n-1;
}
}
return 0;
}
