#include <limits>
#include <initializer_list>
#include <utility>
#include <bitset>
#include <tuple>
#include <type_traits>
#include <functional>
#include <string>
#include <array>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <iterator>
#include <algorithm>
#include <complex>
#include <random>
#include <numeric>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <regex>
#include <cassert>
#include <cstddef>
#include <variant>
#define endl codeforces
#define ALL(v) std::begin(v), std::end(v)
#define ALLR(v) std::rbegin(v), std::rend(v)
using ll = std::int64_t;
using ull = std::uint64_t;
using pii = std::pair<int, int>;
using tii = std::tuple<int, int, int>;
using pll = std::pair<ll, ll>;
using tll = std::tuple<ll, ll, ll>;
template <typename T> using vec = std::vector<T>;
template <typename T> using vvec = vec<vec<T>>;
template <typename T> const T& var_min(const T &t) { return t; }
template <typename T> const T& var_max(const T &t) { return t; }
template <typename T, typename... Tail> const T& var_min(const T &t, const Tail&... tail) { return std::min(t, var_min(tail...)); }
template <typename T, typename... Tail> const T& var_max(const T &t, const Tail&... tail) { return std::max(t, var_max(tail...)); }
template <typename T, typename... Tail> void chmin(T &t, const Tail&... tail) { t = var_min(t, tail...); }
template <typename T, typename... Tail> void chmax(T &t, const Tail&... tail) { t = var_max(t, tail...); }
template <typename T> T make_v(T init) { return init; }
template <typename T, typename... Tail> auto make_v(T init, std::size_t s, Tail... tail) { auto v = std::move(make_v(init, tail...)); return vec<decltype(v)>(s, v); }
template <typename T, std::size_t Head, std::size_t... Tail> struct multi_dem_array { using type = std::array<typename multi_dem_array<T, Tail...>::type, Head>; };
template <typename T, std::size_t Head> struct multi_dem_array<T, Head> { using type = std::array<T, Head>; };
template <typename T, std::size_t... Args> using mdarray = typename multi_dem_array<T, Args...>::type;
namespace init__ { struct InitIO { InitIO() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << std::fixed << std::setprecision(30); } } init_io; }

const std::size_t SIZE = 2010;
mdarray<ll, SIZE, SIZE> dp;
const ll inf = 5e15;

int main() {
    ll n, vmax, l;
    std::cin >> n >> vmax >> l;
    vec<tll> pv(n);
    for (auto &&e : pv) {
        ll x, v, w;
        std::cin >> x >> v >> w;
        e = tll(x, v, w);
    }

    std::fill(ALL(dp[0]), inf);
    dp[0][vmax] = 0;
    ll px = 0;
    for (ll i = 0; i < n; i++) {
        std::fill(ALL(dp[i + 1]), inf);
        ll x, v, w;
        std::tie(x, v, w) = pv[i];
        ll dist = x - px;
        for (ll p = 0; p <= vmax; p++) {
            if (dp[i][p] == inf) continue;
            if (p < dist) continue;
            ll prest = p - dist;
            chmin(dp[i + 1][prest], dp[i][p]);
            chmin(dp[i + 1][std::min(vmax, prest + v)], dp[i][p] + w);
        }
        px = x;
    }

    ll ans = inf;
    ll dist = l - px;
    for (ll i = dist; i <= vmax; i++) chmin(ans, dp[n][i]);
    std::cout << (ans == inf ? -1 : ans) << '\n';
    return 0;
}