#include<bits/stdc++.h>
#define ALL(v) std::begin(v),std::end(v)
using lint=long long;
using ld=long double;
template<class T>using numr=std::numeric_limits<T>;
void cmn(lint&x,lint y){if(x>y)x=y;}
auto min_fn=[](lint x,lint y){return std::min(x,y);};
int main(){
    std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false);
    std::cout.setf(std::ios_base::fixed);std::cout.precision(15);
    lint inf=numr<lint>::max();
    lint n,V,L;std::cin>>n>>V>>L;
    std::vector<lint>x(n+2),v(n+2),w(n+2);
    x.at(n+1)=L;
    for(lint i=1;i<=n;i++)std::cin>>x.at(i)>>v.at(i)>>w.at(i);
    std::vector<lint>dp(V+1,0);
    for(lint i=1;i<=n+1;i++){
        lint d=std::min(V+1,x.at(i)-x.at(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(lint j=V-v.at(i);j>=0;j--)if(dp.at(j)!=inf)cmn(dp.at(j+v.at(i)),dp.at(j)+w.at(i));
        std::partial_sum(dp.rbegin(),dp.rend(),dp.rbegin(),min_fn);
    }
    lint ans=dp.at(0);
    if(ans==inf)ans=-1;
    std::cout<<ans<<'\n';
}