#include<bits/stdc++.h>
void cmn(auto&x,auto y){if(x>y)x=y;}
auto min_fn=[](auto&&x,auto&&y){return std::min(x,y);};
int main(){
    int inf=std::numeric_limits<int>::max();
    int n,V,L;std::cin>>n>>V>>L;
    std::vector<int>x(n+2),v(n+2),w(n+2);
    x[n+1]=L;
    for(int i=1;i<=n;i++)std::cin>>x[i]>>v[i]>>w[i];
    std::vector<int>dp(V+1,0);
    for(int i=1;i<=n+1;i++){
        int d=std::min(V+1,x[i]-x[i-1]);
        std::copy(dp.begin()+std::min(d,V+1),dp.end(),dp.begin());
        std::fill(dp.end()-std::min(d,V+1),dp.end(),inf);
        for(int j=V-v[i];j>=0;j--){
            if(inf-w[i]<=dp[j])continue;
            cmn(dp.at(j+v[i]),dp[j]+w[i]);
        }
        std::partial_sum(dp.rbegin(),dp.rend(),dp.rbegin(),min_fn);
    }
    std::cout<<(dp[0]==inf?-1:dp[0])<<'\n';
}