#include <bits/stdc++.h>
using namespace std;
void setup()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
class SEGMENT_TREE
{
private:
int tree_size;
vector<long long> tree;
inline void Update(int ind, int l, int r, int x, long long v)
{
if (r < x || x < l)
{
return;
}
if (l == r)
{
tree[ind] = min(tree[ind], v);
return;
}
int m = (l + r) >> 1;
Update(ind << 1, l, m, x, v);
Update(ind << 1 | 1, m + 1, r, x, v);
tree[ind] = min(tree[ind << 1], tree[ind << 1 | 1]);
}
inline long long Get(int ind, int l, int r, int x, int y)
{
if (r < x || y < l)
{
return 1e18;
}
if (x <= l && r <= y)
{
return tree[ind];
}
int m = (l + r) >> 1;
return min(Get(ind << 1, l, m, x, y), Get(ind << 1 | 1, m + 1, r, x, y));
}
public:
inline SEGMENT_TREE(int new_size)
{
tree_size = new_size;
tree.clear();
tree.resize(tree_size << 2, 1e18);
}
inline void Update(int x, long long v)
{
Update(1, 1, tree_size, x, v);
}
inline long long Get(int x, int y)
{
return Get(1, 1, tree_size, x, y);
}
} st1(300005), st2(300005);
int n, m, b[300000], k, d[100000];
array<int, 3> a[100000];
long long res = 1e18, t1, t2;
int main()
{
setup();
cin >> m >> n;
for (int i = 0; i < m; ++i)
{
cin >> a[i][0] >> a[i][1] >> a[i][2] >> d[i];
b[i * 3] = a[i][0];
b[i * 3 + 1] = a[i][1];
b[i * 3 + 2] = a[i][2];
}
b[3 * m] = 1;
b[3 * m + 1] = n;
sort(b, b + 3 * m + 2);
k = unique(b, b + 3 * m + 2) - b;
for (int i = 0; i < m; ++i)
{
for (int j = 0; j < 3; ++j)
{
a[i][j] = lower_bound(b, b + k, a[i][j]) - b + 1;
}
}
st1.Update(1, 0);
st2.Update(k, 0);
for (int i = 0; i < m; ++i)
{
t1 = st1.Get(a[i][0], a[i][1]);
t2 = st2.Get(a[i][0], a[i][1]);
res = min(res, t1 + t2 + d[i]);
st1.Update(a[i][2], t1 + d[i]);
st2.Update(a[i][2], t2 + d[i]);
}
cout << (res == 1e18 ? -1 : res);
return 0;
}
