#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << " " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << " " << j << " " << #i << " " << q << " " << #p << endl;
#define show4(x,y) for(auto it:y) cout << it << " "; cout << #x << endl;
typedef pair<long long,int>pii;
//typedef pair<pii,pii>pi2;
typedef array<int,3>pi2;
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
int n,m;
array<int,4>arr[1005]; //l r to cost
int dp[2][605][605];
int sz;
void solve(){
cin >> n >> m;
vector<int>v;
for(int x=0;x<n;x++){
cin >> arr[x][0] >> arr[x][1] >> arr[x][2] >> arr[x][3];
v.push_back(arr[x][0]);
v.push_back(arr[x][1]);
v.push_back(arr[x][2]);
}
v.push_back(1);
v.push_back(m);
sort(v.begin(),v.end());
v.resize(unique(v.begin(),v.end())-v.begin());
for(int x=0;x<n;x++){
arr[x][0]=lower_bound(v.begin(),v.end(),arr[x][0])-v.begin()+1;
arr[x][1]=lower_bound(v.begin(),v.end(),arr[x][1])-v.begin()+1;
arr[x][2]=lower_bound(v.begin(),v.end(),arr[x][2])-v.begin()+1;
}
sz=lower_bound(v.begin(),v.end(),m)-v.begin()+1;
for(int x=0;x<605;x++){
for(int y=0;y<605;y++){
dp[0][x][y]=1e15;
dp[1][x][y]=1e15;
}
}
dp[0][1][0]=0;
for(int x=n-1;x>=0;x--){
for(int l=1;l<=sz;l++){
for(int r=0;r<=sz;r++){
dp[1][l][r]=min(dp[1][l][r],dp[0][l][r]);
int a=arr[x][0];
int b=arr[x][1];
int k=arr[x][2];
int cost=arr[x][3];
if(r<l){
dp[1][a][b]=min(dp[1][a][b],dp[0][l][r]+cost);
}
if(k>=l&&k<=r){
dp[1][min(a,l)][max(b,r)]=min(dp[1][min(a,l)][max(b,r)],dp[0][l][r]+cost);
}
}
}
for(int l=1;l<=sz;l++){
for(int r=0;r<=sz;r++){
dp[0][l][r]=dp[1][l][r];
dp[1][l][r]=1e15;
}
}
}
int hold=dp[0][1][sz];
if(hold>=1e15){
cout << -1;
}
else cout << hold;
}
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
int t=1;
//cin >> t;
while(t--){
solve();
}
}
