#include<bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 3e5 + 5;
struct ttt{
int x, a, b;
} tram[maxn];
bool cmp(ttt c1, ttt c2){
return c1.x < c2.x;
}
int st[4 * maxn], lazy[4 * maxn];
void fix(int id, int l, int r){
if (!lazy[id]) return;
st[id] += lazy[id];
if (l != r){
lazy[id*2] += lazy[id];
lazy[id*2+1] += lazy[id];
}
lazy[id] = 0;
}
void update(int id, int l, int r, int u, int v, int val){
fix(id, l, r);
if (v < l || r < u) return;
if (u <= l && r <= v){
lazy[id] += val;
fix(id, l, r);
return;
}
int mid = l+r>>1;
update(id*2, l, mid, u, v, val);
update(id*2+1, mid+1, r, u, v, val);
st[id] = min(st[id*2], st[id*2+1]);
}
void solve(){
int n, d;cin >> n >> d;
for(int i = 1; i <= n; i++) cin >> tram[i].x >> tram[i].a >> tram[i].b;
sort(tram + 1, tram + n + 1, cmp);
vector<int> v, ans(n + 1);
map<int, vector<int>> mp;
for(int i = 1; i <= n; i++){
v.push_back(tram[i].b);
mp[tram[i].b].push_back(i);
}
sort(v.begin(), v.end());
v.erase(unique(v.begin(), v.end()), v.end());
for(int i = 1; i <= n; i++){
update(1, 1, n, i, i, v[0] - tram[i].x);
int l = i + 1, r = n;
while(l <= r){
int mid = (l + r) / 2;
if(tram[mid].x > tram[i].x){
ans[i] = mid;
r = mid - 1;
}
else l = mid + 1;
}
if(ans[i] > 0) update(1, 1, n, ans[i], n, tram[i].a);
}
int kq = 1e15, z = st[1];
if(z >= 0) kq = min(kq, v[0] - z);
for(int i = 1; i < v.size(); i++){
update(1, 1, n, 1, n, v[i] - v[i - 1]);
for(int y: mp[v[i - 1]]){
if(ans[y] > 0) update(1, 1, n, ans[y], n, -tram[y].a);
}
z = st[1];
if(z >= 0) kq = min(kq, v[i] - z);
}
cout << kq;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
solve();
}
