#include<bits/stdc++.h>

using namespace std;

int n, k;

struct EVE{

    int st,ed,val;

    EVE(){

    }

    EVE(int a,int b, int c){

        st = a, ed = b, val = c;

    }

};

int f,t,c;

vector<EVE> v[];

vector<int> minn[];

int tmp[];

bool cmp(EVE a, EVE b){

    return a.st<b.st;

}

int main(){

    scanf("%d%d",&n,&k);

    for(int i = ;i<n;i++){

        scanf("%d%d%d",&f,&t,&c);

        if(t-f+ >= k) continue;

        v[t-f+].push_back({f,t,c});

    }

    for(int i = ;i<=k;i++) sort(v[i].begin(),v[i].end(),cmp);

    for(int i = ;i<=k;i++){

        for(int j = v[i].size()-;j>=;j--){

            if(j==v[i].size()-) tmp[j]=v[i][j].val;

            else tmp[j]=min(v[i][j].val,tmp[j+]);

        }

        for(int j = ;j<v[i].size();j++){

            minn[i].push_back(tmp[j]);

        }

    }

    long long ans = 1e12;

    for(int i = ;i<=k;i++){

        if(v[k-i].empty()) continue;

        for(int j = ;j<v[i].size();j++){

            int ed = v[i][j].ed;

            long long cost = v[i][j].val;

            int le = , ri = v[k-i].size()-;

            if(v[k-i][ri].st<=ed) continue;

            int mid = le+ri>>;

            while(le<ri){

                mid = le+ri>>;

                if(v[k-i][mid].st<=ed) le = mid+;

                else ri = mid;

            }

            ans = min(ans, cost+minn[k-i][le]);

        }

    }

    if(ans == 1e12) printf("-1");

    else printf("%I64d",ans);

    return ;

}