#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
using namespace std;
typedef long long ll;
constexpr ll INF = 1e18;
void update(int pos, ll val, vector<ll>& tree) {
int n = (int)tree.size()/2;
pos += n;
while(pos > 0) {
tree[pos] = min(tree[pos], val);
pos >>= 1;
}
}
ll query(int l, int r, vector<ll>& tree) {
ll ans = INF;
int n = (int)tree.size()/2;
l += n;
r += n;
for(; l <= r; l>>=1, r>>=1) {
if(l%2==1) {
ans = min(ans, tree[l]);
l++;
}
if(r%2==0) {
ans = min(ans, tree[r]);
r--;
}
}
return ans;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, m;
cin >> m >> n;
vector<tuple<int, int, int, ll>> intervals(m);
vector<int> seen;
for(int i = 0; i < m; i++) {
int a, b, c, d;
cin >> a >> b >> c >> d;
seen.push_back(a);
seen.push_back(b);
seen.push_back(c);
intervals[i] = {a, b, c, d};
}
seen.push_back(1);
seen.push_back(n);
sort(seen.begin(), seen.end());
seen.erase(unique(seen.begin(), seen.end()), seen.end());
vector<ll> leftMinCost(m, INF);
vector<ll> rightMinCost(m, INF);
vector<ll> leftTree(2*seen.size(), INF);
vector<ll> rightTree(2*seen.size(), INF);
update(0, 0, leftTree);
update((int)seen.size()-1, 0, rightTree);
for(int i = 0; i < m; i++) {
get<0>(intervals[i]) = (int)(lower_bound(seen.begin(), seen.end(), get<0>(intervals[i]))-seen.begin());
get<1>(intervals[i]) = (int)(lower_bound(seen.begin(), seen.end(), get<1>(intervals[i]))-seen.begin());
get<2>(intervals[i]) = (int)(lower_bound(seen.begin(), seen.end(), get<2>(intervals[i]))-seen.begin());
int left = get<0>(intervals[i]);
int right = get<1>(intervals[i]);
int hole = get<2>(intervals[i]);
ll cost = get<3>(intervals[i]);
ll minLeft = query(left, right, leftTree);
leftMinCost[i] = min(leftMinCost[i], minLeft+cost);
update(hole, leftMinCost[i], leftTree);
ll minRight = query(left, right, rightTree);
rightMinCost[i] = min(rightMinCost[i], minRight+cost);
update(hole, rightMinCost[i], rightTree);
}
ll best = INF;
for(int i = 0; i < m; i++) {
best = min(best, leftMinCost[i]+rightMinCost[i]-get<3>(intervals[i]));
}
if(best == INF)
cout << -1 << "\n";
else
cout << best << "\n";
}
