#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template <class T, class U> using Pa = pair<T, U>;
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vec<T>>;

void chmin(ll &a,ll b){if(a>b) a = b;}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N,V,L;
    cin >> N >> V >> L;
    vec<int> x(N+2),v(N+2),w(N+2);
    for(int i=1;i<=N;i++) cin >> x[i] >> v[i] >> w[i];
    ll inf = 1e18;
    x[N+1] = L;
    vvec<ll> dp(N+2,vec<ll>(V+1,inf));
    dp[0][V] = 0;
    for(int i=1;i<=N+1;i++) for(int j=0;j<=V;j++){
        int d = x[i]-x[i-1];
        if(d<=j) chmin(dp[i][j-d],dp[i-1][j]);
        if(i!=1){
            int nj = min(V,j+v[i-1]);
            if(d<=nj) chmin(dp[i][nj-d],dp[i-1][j]+w[i-1]); 
        }
    }
    ll ans = inf;
//    for(int i=0;i<=N+1;i++) for(int j=0;j<=V;j++) cerr << dp[i][j] << (j!=V? " ":"\n");
    for(int j=0;j<=V;j++) chmin(ans,dp[N+1][j]);
    cout << (ans!=inf? ans:-1) << "\n";
}