#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define sz(x) (int) (x).size()
#define L first
#define R second
using namespace std;
typedef long long lint;
typedef pair<int,int> ii;
const lint inf = 1e17;
struct node{
int s, e, m;
lint val;
node *l = nullptr, *r = nullptr;
node(int S, int E){
s = S, e = E, m = (s+e)/2;
val = inf;
}
void create(){
if(s != e){
l = new node(s,m);
r = new node(m+1,e);
}
}
void update(int P, lint V){
val = min(val, V);
if(s == e) return;
else if(P <= m){
if(l == nullptr) create();
l->update(P,V);
}
else{
if(r == nullptr) create();
r->update(P,V);
}
}
lint query(int S, int E){
if(s == S && E == e) return val;
else{
if(l == nullptr) create();
if(E <= m) return l->query(S,E);
else if(S >= m+1) return r->query(S,E);
else return min(l->query(S,m), r->query(m+1,E));
}
}
} *Left, *Right;
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
int n, len; cin >> n >> len;
Left = new node(1, len), Right = new node(1, len);
Left->update(1, 0); Right->update(len, 0);
lint ans = inf;
for(int i = 0;i < n;i++){
int L, R, M, cost; cin >> L >> R >> M >> cost;
lint fromLeft = Left->query(L, R);
lint fromRight = Right->query(L, R);
ans = min(ans, fromLeft + fromRight + cost);
Left->update(M, fromLeft + cost);
Right->update(M, fromRight + cost);
}
if(ans == inf) ans = -1;
cout << ans;
}
