#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb push_back
const int MAX_N = 3e5;
struct FuelStation {
int d, maxl, th;
};
FuelStation fs[MAX_N + 2];
set<pair<int, int>, greater<pair<int, int>>> rem;
int main () {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n, d, i, sf, ff, fcap;
cin >> n >> d;
for (i = 1; i <= n; i++) {
cin >> fs[i].d >> fs[i].maxl >> fs[i].th;
}
sort(fs + 1, fs + n + 1,
[] (FuelStation s1, FuelStation s2) { return s1.d < s2.d; });
fs[n + 1] = {d, -1, d + 1};
sf = 0;
ff = 0;
for (i = 1; i <= n + 1; i++) {
fcap = sf + ff;
while (fs[i].d > fcap && sf <= fs[i].th) {
sf = fs[i].d - ff;
while (rem.size() > 0 && (*rem.begin()).first < sf) {
ff -= (*rem.begin()).second;
rem.erase(*rem.begin());
}
fcap = sf + ff;
}
if (sf <= fs[i].th) {
ff += fs[i].maxl;
rem.emplace(fs[i].th, fs[i].maxl);
}
}
cout << sf << "\n";
return 0;
}
