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

class segment_tree{
    int64_t tree[4002];
    size_t len;
public:
    segment_tree(int64_t n): len(n){ }
    void init(int64_t *val){
        for(int i=0;i<len;++i) tree[len+i] = val[i];
        for(int i=len-1;i>0;--i) tree[i] = min(tree[i<<1 | 0], tree[i<<1 | 1]);
    }
    int64_t get(int64_t left, int64_t right){
        left += len; right += len;
        int64_t ret = INT64_MAX;
        while(left < right){
            if(left & 1) ret = min(ret, tree[left++]);
            if(right & 1) ret = min(ret, tree[--right]);
            left >>= 1; right >>= 1;
        }
        return ret;
    }
};

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    int64_t n, v, l, x[2002], a[2001], c[2001];
    cin >> n >> v >> l;
    x[0] = 0;
    for(int i=1;i<=n;++i) cin >> x[i] >> a[i] >> c[i];

    segment_tree st{v+1};
    static int64_t dp[2001][2001];
    for(int i=0;i<=v;++i) dp[0][i] = 0;
    for(int i=1;i<=n;++i){
        int64_t d = x[i] - x[i-1];
        st.init(dp[i-1]);
        for(int j=0;j<=v;++j){
            dp[i][j] = j+d<=v ? dp[i-1][j+d] : INT64_MAX;
            auto cand = st.get(max(j+d-a[i], d), min(j+d, v+1));
            if(cand < INT64_MAX) dp[i][j] = min(dp[i][j], cand + c[i]);
        }
    }
    st.init(dp[n]);
    auto ans = st.get(l-x[n], v+1);
    cout << (ans == INT64_MAX ? -1 : ans) << endl;

    return 0;
}