#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
const ll mod = 1e9 + 7;
//const ll mod = 998244353;
#define REP(i,n) for(int i=0;i<(int)n;++i)
//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){
os << "(" << v.first << ", " << v.second << ")"; return os;
}
template<class T> ostream& operator << (ostream& os, const vector<T> v){
for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << " ";} os << v[i];} return os;
}
template<class T> ostream& operator << (ostream& os, const vector<vector<T>> v){
for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << endl;} os << v[i];} return os;
}
string num2bit(ll num, ll len){
    string bit = "";
    REP(i, len){
    bit += char('0'+(num>>i & 1));
    }
    return bit;
}

ll dp[2020][2020];

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    ll N, V, L;
    cin >> N >> V >> L;

    vector<ll> x(N), v(N), w(N);
    REP(i, N) cin >> x[i] >> v[i] >> w[i];
    x.push_back(L);
    v.push_back(0);
    w.push_back(0);

    const ll INF = (1ll<<60);
    REP(i, 2020)REP(j, 2020) dp[i][j] = INF;
    dp[0][V] = 0;

    REP(i, N+1){
        REP(j, V+1){
            if(dp[i][j]==INF) continue;
            ll dist = (i==0 ? x[0] : x[i] - x[i-1]);
            if(j<dist) continue;
            chmin(dp[i+1][j-dist], dp[i][j]);
            chmin(dp[i+1][min(j-dist+v[i], V)], dp[i][j]+w[i]);
        }
    }

    ll res = INF;
    REP(i, V+1) chmin(res, dp[N+1][i]);
    cout << (res==INF ? -1 : res) << endl;
    return 0;
}