#include <bits/stdc++.h>
using namespace std;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}
using Int = long long;
const char newl = '\n';


template<typename T> void drop(const T &x){cout<<x<<endl;exit(0);}

//INSERT ABOVE HERE
signed main(){
  cin.tie(0);
  ios::sync_with_stdio(0);

  Int n,v,l;
  cin>>n>>v>>l;

  const Int MAX = 1e7;
  if(l>=MAX) drop(-1);

  // O(N+V+L) <- usoyanke uku

  vector<Int> xs(n),vs(n),ws(n);
  for(Int i=0;i<n;i++)
    cin>>xs[i]>>vs[i]>>ws[i];

  const Int INF = 1e15;
  xs.emplace_back(l);
  vs.emplace_back(0);
  ws.emplace_back(INF);

  // keep dp[i]<=dp[i+1]
  deque<Int> dp(v+1,0);
  Int lst=0;
  for(Int i=0;i<=n;i++){
    if(xs[i]-lst>v) drop(-1);
    for(Int j=0;j<xs[i]-lst;j++){
      dp.pop_front();
      dp.emplace_back(INF);
    }
    lst=xs[i];
    for(Int j=v;j>=0;j--)
      chmin(dp[min(j+vs[i],v)],dp[j]+ws[i]);

    for(Int j=v;j>0;j--) chmin(dp[j-1],dp[j]);
  }

  cout<<dp[0]<<newl;
  return 0;
}