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