#include <bits/stdc++.h>
using namespace std;
typedef long long int64;
const int maxn = 1e5 + 2;
int n,m;
struct node {
int64 v;
node* left;
node* right;
node(int64 _v): v(_v) {};
void extend() {
if (left != NULL) return;
left = new node(1e15);
right = new node(1e15);
}
int64 query (int l, int r, int il, int ir) {
if (il <= l && r <= ir) return v;
if (l > ir || r < il) return 1e15;
extend();
int mid = (l + r) / 2;
return min(left->query(l, mid, il, ir), right->query(mid + 1, r, il, ir));
}
void update (int l, int r, int x, int64 nval) {
if (l == r && l == x) return void(v = min(v, nval));
if (l > x || r < x) return;
extend();
int mid = (l + r) / 2;
left->update(l, mid, x, nval);
right->update(mid + 1, r, x, nval);
v = min(left->v, right->v);
}
};
int main() {
cin >> n >> m;
node* lf = new node(1e15);
node* rt = new node(1e15);
int64 rs = 1e15;
lf->update(1, m, 1, 0);
rt->update(1, m, m, 0);
for (int i = 0; i < n; i++){
int64 a,b,c,cost;
cin >> a >> b >> c >> cost;
int64 p1 = lf->query(1, m, a,b);
int64 p2 = rt->query(1, m, a,b);
rs = min(rs, p1 + p2 + cost);
lf->update(1, m, c, p1 + cost);
rt->update(1, m, c, p2 + cost);
}
cout << (rs >= 1e15 ? -1: rs);
}
