#include <bits/stdc++.h>
using namespace std;
#define int long long
vector<int> d;
int idx(int k){
auto it = lower_bound(d.begin(), d.end(), k);
return (it - d.begin());
}
vector<int> t;
void update(int i, int l, int r, int i1, int v){
if(l == r){
t[i] = v;
return;
}
int mid = (l+r)/2;
if(i1 <= mid){
update(i*2, l, mid, i1, v);
}else{
update(i*2+1, mid+1, r, i1, v);
}
t[i] = min(t[i*2], t[i*2+1]);
}
int query(int i, int l, int r, int l1, int r1){
if(l > r1 || l1 > r){
return 2e18;
}
if(l1 <= l && r1 >= r){
return t[i];
}
int mid = (l + r)/2;
return min(query(i*2, l, mid, l1, r1), query(i*2+1, mid+1, r, l1, r1));
}
vector<int> t1;
void update1(int i, int l, int r, int i1, int v){
if(l == r){
t1[i] = v;
return;
}
int mid = (l+r)/2;
if(i1 <= mid){
update1(i*2, l, mid, i1, v);
}else{
update1(i*2+1, mid+1, r, i1, v);
}
t1[i] = min(t1[i*2], t1[i*2+1]);
}
int query1(int i, int l, int r, int l1, int r1){
if(l > r1 || l1 > r){
return 2e18;
}
if(l1 <= l && r1 >= r){
return t1[i];
}
int mid = (l + r)/2;
return min(query1(i*2, l, mid, l1, r1), query1(i*2+1, mid+1, r, l1, r1));
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int m, n; cin >> m >> n;
vector<array<int, 4>> x(m);
for(int i = 0; i < m; i++){
cin >> x[i][0] >> x[i][1] >> x[i][2] >> x[i][3];
d.push_back(x[i][0]);
d.push_back(x[i][1]);
d.push_back(x[i][2]);
}
d.push_back(1);
d.push_back(n);
sort(d.begin(), d.end());
d.erase(unique(d.begin(), d.end()), d.end());
t.resize(d.size()*4, 2e18);
t1.resize(d.size()*4, 2e18);
vector<int> dp(d.size(), 2e18);
update(1, 0, d.size()-1, 0, 0);
t1.resize(d.size()*4, 2e18);
vector<int> dp1(d.size(), 2e18);
update1(1, 0, d.size()-1, d.size()-1, 0);
int mn = 2e18;
dp[0] = 0;
dp1[d.size()-1] = 0;
for(int i = 0; i < m; i++){
int l, r;
l = idx(x[i][0]);
r = idx(x[i][1]);
int c = idx(x[i][2]);
int j = query(1, 0, d.size()-1, l, r);
int raveluk = -1;
if(j != 2e18){
dp[c] = min(dp[c], j + x[i][3]);
update(1, 0, d.size()-1, c, dp[c]);
raveluk = j;
}
j = query1(1, 0, d.size()-1, l, r);
if(j == 2e18) continue;
dp1[c] = min(dp1[c], j + x[i][3]);
update1(1, 0, d.size()-1, c, dp1[c]);
int h = j + x[i][3];
if(raveluk == -1) continue;
mn = min(mn, raveluk + h);
}
if(mn == 2e18){
mn = -1;
}
cout << mn << "\n";
return 0;
}
