#include<cstdio>
#include<cstring>
#include<iostream>
#include<cmath>
#include<ctime>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<stack>
#include<map>
using namespace std;
typedef long long LL;
const int MR=2e3+10;
int n,V,L;
int x[MR],v[MR],w[MR];
LL dp[MR][MR];
//dp[i][j]是到加油站i且油量剩j时的最少花费
int main(){
    cin>>n>>V>>L;
    for(int i=1;i<=n;i++){
        cin>>x[i]>>v[i]>>w[i];
    }
    x[n+1]=L;
    memset(dp,0x3f,sizeof(dp));
    dp[0][V]=0;
    for(int i=0;i<=n;i++){
        for(int j=0;j<=V;j++){
            int t=x[i+1]-x[i];
            //不加油直接出发,到下个站要消耗t
            if(j>=t) dp[i+1][j-t]=min(dp[i+1][j-t],dp[i][j]);
            //加油后出发，到下个站剩余 min(j+v[i],V)-t
            if(min(j+v[i],V)>=t){
                dp[i+1][min(j+v[i],V)-t]=min(dp[i+1][min(j+v[i],V)-t],dp[i][j]+w[i]);
            }
        }
    }
    LL ans=1e18;
    for(int j=0;j<=V;j++) ans=min(ans,dp[n+1][j]);
    if(ans<1e18) cout<<ans<<endl;
    else cout<<-1<<endl;
    return 0;
}