#include<bits/stdc++.h>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef double db;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define pbds tree<pair<int, int>, null_type, less<pair<int, int>>,rb_tree_tag, tree_order_statistics_node_update>
using namespace __gnu_pbds;
ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (PGCD)
ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);} // least common multiple (PPCM)
int dx[8] = {1, 0, 0, -1, 1, 1, -1, -1};
int dy[8] = {0, 1, -1, 0, 1, -1, -1, 1};
#define endl "\n"
#define ss second
#define ff first
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define vi vector<int>
#define vii vector<pair<int,int>>
#define vl vector<ll>
#define vll vector<pair<ll,ll>>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pdd pair<double,double>
#define vdd vector<pdd>
#define speed ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
////////////////////Only Clear Code//////////////////////////
void usaco_problem(){
freopen("milkvisits.in", "r", stdin);
freopen("milkvisits.out", "w", stdout);
}
void init(){
#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif // ONLINE_JUDGE
}
const int mx = 1005;
const int LOG = 25;
const ll inf = 1e9;
const ll mod = 1e9+7;
int a[mx], b[mx], c[mx], d[mx];
set<int> nxt[mx];
int n, m;
bool verify(vector<vi> v){
sort(all(v));
if(v[0][0] != 1)return 0;
int r = v[0][1];
for(int i = 1; i < n;i++){
if(v[i][0] > r+1){
return 0;
}
r = max(r, v[i][1]);
}
if(r != m)return 0;
int c = 0;
for(int i = 0; i < n;i++){
if(nxt[i].empty())c++;
}
if(c >= 2){
return 0;
}
return 1;
}
void run_case(){
cin >> n >> m;
vector<vi> v;
ll cost = 0;
for(int i = 0; i < n;i++){
cin >> a[i] >> b[i] >> c[i] >> d[i];
v.pb({a[i], b[i], i});
cost += d[i];
}
for(int i = 0; i < n;i++){
for(int j = i+1;j < n;j++){
if(c[i] >= a[j] && c[i] <= b[j]){
nxt[i].insert(j);
}
}
}
if(!verify(v)){
cout << -1 << endl;
return;
}
for(int i = n-1;i >= 0;i--){
bool ok = 1;
int l = inf, r = -inf;
for(int k = 0; k < n;k++){
if(v[k][2] == i)continue;
if(r != -inf && v[k][0] > r+1){
ok = 0;
}
l = min(l, v[k][0]);
r = max(r, v[k][1]);
}
if(r != m || l != 1)ok = 0;
if(!ok)continue;
for(int j = i-1;j >= 0;j--){
if(nxt[j].size() == 1 && nxt[j].count(i)){
ok = 0;
}
}
if(ok){
for(int j = i-1;j >= 0;j--){
nxt[j].erase(i);
}
cost -= d[i];
}
}
cout << cost << endl;
}
int main(){
speed;
int t;
//cin >> t;
t = 1;
while(t--){
run_case();
}
}
/*
NEVER GIVE UP!
DOING SMTHNG IS BETTER THAN DOING NTHNG!!!
Your Guide when stuck:
- Continue keyword only after reading the whole input
- Don't use memset with testcases
- Check for corner cases(n=1, n=0)
- Check where you declare n(Be careful of declaring it globally and in main)
*/
