#include <bits/stdc++.h> // #define int long long using namespace std; 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 map<pair<int, 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(!best.contains({arr[i].first.first, arr[i].first.second})) { best[{arr[i].first.first,arr[i].first.second}] = arr[i].second.second; }else { best[{arr[i].first.first, arr[i].first.second}] = min(best[{arr[i].first.first, arr[i].first.second}], arr[i].second.second); } for(pair<pair<int, int>, int> j : best) { if(arr[i].second.first >= j.first.first && arr[i].second.first <= j.first.second) { int left = min(j.first.first, arr[i].first.first); int right = max(j.first.second, arr[i].first.second); if(!best.contains({left, right})) { best[{left, right}] = j.second + arr[i].second.second; }else { best[{left, right}] = min(best[{left, right}], j.second + arr[i].second.second); } } } } if(!best.contains({1, n})) { cout<<-1<<'\n'; }else { cout<<best[{1, n}]<<'\n'; } return 0; }