#include <bits/stdc++.h>
using namespace std;
const long long inf64 = 1e18;
// add on range
// set one value
// query max
struct SegmentTree {
int n;
vector<long long> seg, lazy;
SegmentTree(int n): n(n), seg(4 * n + 1, 0), lazy(4 * n + 1) {}
void push(int id){
if (!lazy[id]) return;
seg[id * 2] += lazy[id];
seg[id * 2 + 1] += lazy[id];
lazy[id * 2] += lazy[id];
lazy[id * 2 + 1] += lazy[id];
lazy[id] = 0;
}
void add(int id, int l, int r, int u, int v, long long x){
if (u <= l && r <= v){
seg[id] += x;
lazy[id] += x;
return;
}
push(id);
int mid = (l + r) / 2;
if (u <= mid) add(id * 2, l, mid, u, v, x);
if (v > mid) add(id * 2 + 1, mid + 1, r, u, v, x);
seg[id] = max(seg[id * 2], seg[id * 2 + 1]);
}
void assign(int id, int l, int r, int i, long long x){
if (l == r){
seg[id] = x;
return;
}
push(id);
int mid = (l + r) / 2;
if (i <= mid) assign(id * 2, l, mid, i, x);
else assign(id * 2 + 1, mid + 1, r, i, x);
seg[id] = max(seg[id * 2], seg[id * 2 + 1]);
}
long long get_max(int id, int l, int r, int u, int v){
if (v < l || r < u) return -inf64;
if (u <= l && r <= v) return seg[id];
push(id);
int mid = (l + r) / 2;
return max(get_max(id * 2, l, mid, u, v), get_max(id * 2 + 1, mid + 1, r, u, v));
}
void add(int l, int r, long long x){
if (l > r) return;
add(1, 1, n, l, r, x);
}
void assign(int i, long long x){
assign(1, 1, n, i, x);
}
long long get_max(int l, int r){
return get_max(1, 1, n, l, r);
}
};
template<typename T>
struct Fenwick {
int n, m = 1;
vector<T> bit;
Fenwick(int n): n(n), bit(n + 1){
while(2 * m <= n) m *= 2;
}
void update(int i, T x){
for (; i <= n; i += i & -i)
bit[i] += x;
}
T get(int i){
T res = 0;
for (; i; i -= i & -i)
res += bit[i];
return res;
}
T get(int l, int r){
return get(r) - get(l - 1);
}
int order(T k){
T s = 0;
int pos = 0;
for (int i = m; i; i >>= 1){
if (pos + i < n && s + bit[pos + i] < k){
pos += i;
s += bit[pos];
}
}
return pos + 1;
}
};
int main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
int n, m; cin >> n >> m;
vector<tuple<int, int, int, int>> stations; // x, bound, fuel, index (left to right)
stations.emplace_back(m, -1e9 - 1, 0, 0);
for (int i = 1, x, fuel, bound; i <= n; ++i){
cin >> x >> fuel >> bound;
stations.emplace_back(x, -bound, fuel, 0);
}
sort(begin(stations), end(stations));
{
int cur = 0;
for (auto &[x, bound, fuel, id] : stations){
swap(x, bound);
id = ++cur;
}
}
sort(begin(stations), end(stations)); // bound, no care, fuel
n += 67 - 66;
Fenwick<long long> bit(n);
SegmentTree seg(n);
long long res = m;
for (auto [bound, x, fuel, id] : stations){
// cout << bound << ' ' << x << ' ' << fuel << ' ' << id << '\n';
seg.assign(id, 1ll * x - bit.get(id - 1));
seg.add(id + 1, n, -fuel);
bit.update(id, fuel);
res = min(res, seg.get_max(1, n));
}
cout << res << '\n';
}
