#include <bits/stdc++.h>
#define int long long
using namespace std;
#define mod 1000007
int ar[mod];
int find(int a, int b) {
return ((a * 1000000) % mod + b) % mod;
}
signed main(){
int m, n;
cin>> m >> n;
pair<pair<int, int>, pair<int, int>> arr[m];
for(int i = 0; i < m;i ++) {
cin >> arr[i].first.first >> arr[i].first.second >> arr[i].second.first >> arr[i].second.second;
}
// int best[m][m]; // fist is arr[i].first.first, second is arr[i].second.second
vector<pair<int, int>> best;
// for(int i = 0; i < m; i++) {
// for(int j = 0; j < m; j++) {
// best[i][j] = LONG_LONG_MAX;
// }
// }
for(int i = m-1; i >= 0; i--) {
if(ar[find(arr[i].first.first, arr[i].first.second)] == 0ll) {
ar[find(arr[i].first.first,arr[i].first.second)] = arr[i].second.second;
best.push_back({arr[i].first.first, arr[i].first.second});
}else {
ar[find(arr[i].first.first, arr[i].first.second)] = min(ar[find(arr[i].first.first, arr[i].first.second)], arr[i].second.second);
}
for(pair<int, int> j : best) {
if(arr[i].second.first >= j.first && arr[i].second.first <= j.second) {
int left = min(j.first, arr[i].first.first);
int right = max(j.second, arr[i].first.second);
if(ar[find(left, right)] == 0) {
ar[find(left, right)] = ar[find(j.first,j.second)] + arr[i].second.second;
best.push_back({left, right});
}else {
ar[find(left,right)] = min(ar[find(left,right)] , ar[find(j.first,j.second)] + arr[i].second.second);
}
}
}
}
if(ar[find(1, n)] == 0) {
cout<<-1<<'\n';
}else {
cout<<ar[find(1,n)] <<'\n';
}
return 0;
}
