#include <bits/stdc++.h>

using namespace std;

vector < pair < long long, long long > > v[200100];
vector < pair < long long, long long > >::iterator it;
long long l[200100],r[200100],c[200100];
int main()
{
    long long n, x,Answer = 2e18,Min;
    cin>>n>>x;
    for(int i=0; i<n; i++)
    {
        cin>>l[i]>>r[i]>>c[i];
        v[(r[i]-l[i]+1)].push_back(make_pair(l[i],c[i]));
    }
    for(int i=1; i<=2e5; i++)
    {
        Min = 1e18;
        if(v[i].size()>=2)
        {
            sort(v[i].begin(),v[i].end());
            for(int j=v[i].size()-1; j>=0; j--)
            {
                v[i][j].second = min(v[i][j].second,Min);
                Min=min(Min,v[i][j].second);
            }
        }
    }
    for(int i=0; i<n; i++)
    {
        if(x-(r[i]-l[i]+1) <= 0)  continue;
        it = upper_bound(v[x-(r[i]-l[i]+1)].begin(),v[x-(r[i]-l[i]+1)].end(),pair < long long, long long >(r[i],-1));
        if(it==v[x-(r[i]-l[i]+1)].end())  continue;
        else  Answer = min(Answer, c[i] + it->second);
    }
    Answer == 2e18 ? cout<<"-1" : cout<<Answer;
    return 0;
}