#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
#define X first
#define Y second
#define PB push_back
using namespace std;
typedef long long ll;
typedef pair < ll, ll > pll;
const int N = 3e5 + 500;
const ll INF = 1e15;
const int OFF = (1 << 19);
int m, n, L[N], R[N], C[N], Q[N];
vector < int > saz;
pll T[2 * OFF], NULA = {INF, INF};
pll mrg(pll A, pll B){
return {min(A.X, B.X), min(A.Y, B.Y)};
}
void update(int i, pll nw){
T[OFF + i] = mrg(T[OFF + i], nw);
for(i = (i + OFF) / 2 ; i ; i /= 2)
T[i] = mrg(T[2 * i], T[2 * i + 1]);
}
pll query(int i, int a, int b, int lo, int hi){
if(lo <= a && b <= hi)
return T[i];
if(a > hi || b < lo)
return NULA;
return mrg(query(2 * i, a, (a + b) / 2,lo, hi), query(2 * i + 1, (a + b) / 2 + 1, b, lo, hi));
}
int main(){
for(int i = 0;i < 2 * OFF;i++)
T[i] = NULA;
scanf("%d%d", &m, &n);
saz.PB(1); saz.PB(n);
for(int i = 0;i < m;i++){
scanf("%d%d%d%d", L + i, R + i, Q + i, C + i);
saz.PB(L[i]); saz.PB(R[i]); saz.PB(Q[i]);
}
sort(saz.begin(), saz.end());
saz.erase(unique(saz.begin(), saz.end()), saz.end());
n = (int)saz.size() - 1;
update(0, {0, INF}); update(n, {INF, 0});
for(int i = 0;i < m;i++){
L[i] = lower_bound(saz.begin(), saz.end(), L[i]) - saz.begin();
R[i] = lower_bound(saz.begin(), saz.end(), R[i]) - saz.begin();
Q[i] = lower_bound(saz.begin(), saz.end(), Q[i]) - saz.begin();
}
ll sol = INF;
for(int i = 0;i < m;i++){
pll ja = query(1, 0, OFF - 1, L[i], R[i]);
sol = min(sol, ja.X + ja.Y + C[i]);
ja.X += C[i], ja.Y += C[i];
//printf("%lld %lld\n", ja.X, ja.Y);
update(Q[i], ja);
}
if(sol == INF)
printf("-1\n");
else
printf("%lld\n", sol);
return 0;
}
