#include <bits/stdc++.h>
#define For(i, a, b) for(int (i)=(int)(a); (i)<(int)(b); ++(i))
#define rFor(i, a, b) for(int (i)=(int)(a)-1; (i)>=(int)(b); --(i))
#define rep(i, n) For((i), 0, (n))
#define rrep(i, n) rFor((i), (n), 0)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef unsigned long long ulint;
typedef pair<int, int> pii;
typedef pair<lint, lint> pll;
template<class T> bool chmax(T &a, const T &b){if(a<b){a=b; return true;} return false;}
template<class T> bool chmin(T &a, const T &b){if(a>b){a=b; return true;} return false;}
template<class T> T div_floor(T a, T b){
    if(b < 0) a *= -1, b *= -1;
    return a>=0 ? a/b : (a+1)/b-1;
}
template<class T> T div_ceil(T a, T b){
    if(b < 0) a *= -1, b *= -1;
    return a>0 ? (a-1)/b+1 : a/b;
}

constexpr lint mod = 1e9+7;
constexpr lint INF = mod * mod;
constexpr int MAX = 200010;

lint dp[2010][2010];

int main(){
    int n, V, L;
    scanf("%d%d%d", &n, &V, &L);
    int x[n+2]; lint v[n+2], w[n+2];
    x[0] = v[0] = w[0] = 0;
    x[n+1] = L; v[n+1] = 0; w[n+1] = 0;
    For(i, 1, n+1) scanf("%d%lld%lld", &x[i], &v[i], &w[i]);
    rep(i, n+2)rep(j, V+1) dp[i][j] = INF;
    dp[0][V] = 0;
    rep(i, n+1)rep(j, V+1)if(dp[i][j] < INF){
        lint nv = min((lint)V, j+v[i]);
        int d = x[i+1] - x[i];
        if(nv < d) continue;
        chmin(dp[i+1][nv-d], dp[i][j] + w[i]);
        if(j >= d) chmin(dp[i+1][j-d], dp[i][j]);
    }
    lint ans = INF;
    rep(j, V+1) chmin(ans, dp[n+1][j]);
    printf("%lld\n", ans == INF ? -1 : ans);
}