#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 3e5 + 5;
int n, d;
tuple<int, int, int> a[N];
bool ok(int x){
vector<tuple<int, int, int>> v;
v.push_back({0, 0, 0});
for(int i = 1;i<=n;i++){
if(get<2>(a[i]) >= x) v.push_back(a[i]);
}
int cur = x;
v.push_back({d, 0, 0});
for(int i = 1;i<v.size();i++){
cur -= (get<0>(v[i]) - get<0>(v[i - 1]));
if(cur < 0) return 0;
cur += get<1>(v[i]);
}
return 1;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> d;
vector<int> cand = {0};
for(int i = 1;i<=n;i++){
auto &[x, b, c] = a[i];
cin >> x >> b >> c;
cand.push_back(c);
}
cand.push_back(1e9);
sort(a + 1, a + n + 1);
sort(cand.begin(), cand.end());
int ans = d;
for(auto x : cand){
++x;
vector<tuple<int, int, int>> v;
v.push_back({0, 0, 0});
for(int i = 1;i<=n;i++){
if(get<2>(a[i]) >= x) v.push_back(a[i]);
}
v.push_back({d, 0, 0});
int cur = x, cc = x;
for(int i = 1;i<v.size();i++){
cur -= (get<0>(v[i]) - get<0>(v[i - 1]));
if(cur < 0){
cc -= cur;
cur = 0;
}
cur += get<1>(v[i]);
}
ans = min(ans, cc);
}
cout << ans;
}
