#include <bits/stdc++.h>
using namespace std;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

typedef long long ll;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<long long> VL;
typedef vector<vector<long long>> VVL;
typedef vector<string> VS;
typedef pair<int, int> P;
typedef tuple<ll,ll,ll,ll> tpl;

#define ALL(a)  (a).begin(),(a).end()
#define SORT(c) sort((c).begin(),(c).end())
#define REVERSE(c) reverse((c).begin(),(c).end())
#define LB(a,x) lower_bound((a).begin(), (a).end(), x) - (a).begin()
#define UB(a,x) upper_bound((a).begin(), (a).end(), x) - (a).begin()

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define RFOR(i,a,b) for(int i=(a)-1;i>=(b);--i)
#define RREP(i,n) RFOR(i,n,0)

#define en "\n"

constexpr double EPS = 1e-9;
constexpr double PI  = 3.141592653589793238462643383279;
constexpr int INF = 2147483647;
constexpr long long LINF = 1LL<<60;
constexpr long long MOD = 1000000007; // 998244353;

#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

int main(void){
    ll N,V,L; cin >> N >> V >> L;

    VI x(N+2,0), v(N), w(N); x[N+1] = L;
    REP(i,N) cin >> x[i+1] >> v[i] >> w[i];

    ll dp[N+2][V+1][2]; REP(i,N+2)REP(j,V+1)REP(k,2) dp[i][j][k] = LINF;
    ll ans = LINF;
    priority_queue<tpl,vector<tpl>,greater<tpl>> q;
    q.push(tpl(0, 0, V, 0));
    while(q.size()){
        ll cost, n, p, k;
        tie(cost, n, p, k) = q.top(); q.pop();

        if(dp[n][p][k] < LINF) continue;
        dp[n][p][k] = cost;
        if(n == N+1){
            chmin(ans, cost);
            continue;
        }

        if(k == 1 && cost+w[n-1] < ans)  q.push(tpl(cost+w[n-1], n, min(V,p+v[n-1]), 0));
        ll len = x[n+1] - x[n];
        if(p - len < 0) continue;
        if(cost < ans) q.push(tpl(cost, n+1, p-len, 1));
    }

    cout << (ans<LINF ? ans : -1) << en;
    return 0;
}