#include <bits/stdc++.h>

 #define lson l,m,rt*2

 #define rson m+1,r,rt*2+1

 using namespace std;

 typedef long long LL;

 struct node {

     LL l,r,s;

     bool operator < (const node& t) const {

         return r<t.r;

     }

 };

 const int N=2e5+;

 const int MAX=0x3f3f3f3f;

 node a[N];

 LL b[N]; int cnt;

 int  tree[N*];

 int n; LL M,E;

 LL ans;

 inline void pushup (int rt) {

     tree[rt]=min (tree[rt*],tree[rt*+]);

 }

 inline int mapp (LL x) {

     return lower_bound(b+,b++cnt,x)-b;

 }

 void update (int p,int k,int l,int r,int rt) {

     if (l==r) {

         tree[rt]=min (k,tree[rt]);

         return ;

     }

     int m=(l+r)/;

     if (p<=m) update (p,k,lson);

     else      update (p,k,rson);

     pushup(rt);

     return ;

 }

 int query (int L,int R,int l,int r,int rt) {

     if (l>=L&&r<=R)  return tree[rt];

     if (l>R||r<L)    return MAX;

     int m=(l+r)/;

     return min (query(L,R,lson),query(L,R,rson));

 }

 int main ()

 {

     while (~scanf ("%d %lld %lld",&n,&M,&E)) {

           cnt=;

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

             scanf ("%lld %lld %lld",&a[i].l,&a[i].r,&a[i].s);

             a[i].l--;

             b[++cnt]=a[i].l; b[++cnt]=a[i].r;

           }

           sort (b+,b++cnt); cnt=;

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

             if (b[i]!=b[cnt])

                 b[++cnt]=b[i];

           if (b[]!=M-||b[cnt]!=E)  ans=-;

           else {

                 memset (tree,0x3f,sizeof(tree));

                 sort (a+,a++n);

                 update (,,,cnt,);

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

                     int r=mapp(a[i].r);

                     int l=mapp(a[i].l);

                     int tmp=query (l,r,,cnt,);

                     update (r,tmp+a[i].s,,cnt,);

                 }

                 ans=query (cnt,cnt,,cnt,);

                 if (ans==MAX)  ans=-;

           }

           printf("%d\n",ans);

     }

     return ;

 }