#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<iomanip>
#include<math.h>
#include<complex>
#include<queue>
#include<deque>
#include<stack>
#include<map>
#include<set>
#include<bitset>
#include<functional>
#include<assert.h>
#include<numeric>
using namespace std;
#define REP(i,m,n) for(int i=(int)(m) ; i < (int) (n) ; ++i )
#define rep(i,n) REP(i,0,n)
using ll = long long;
const int inf=1e9+7;
const ll longinf=1LL<<60 ;
const ll mod=1e9+7 ;


int main(){
    int n,v,l;
    cin>>n>>v>>l;
    vector<int> x(n+2),a(n+2),w(n+2);
    rep(i,n){
        cin>>x[i+1]>>a[i+1]>>w[i+1];
    }
    a[0]=v;
    x[n+1]=l;
    vector<vector<ll>> dp(n+3,vector<ll>(v+1,longinf));
    dp[0][0]=0;
    rep(i,n+1){
        rep(j,v+1){
            int next=x[i+1]-x[i];
            if(j-next>=0)dp[i+1][j-next]=min(dp[i+1][j-next],dp[i][j]);
            int nv=min(v-next,j+a[i]-next);
            if(nv>=0)dp[i+1][nv]=min(dp[i+1][nv],dp[i][j]+w[i]);
        }
        for(int j=v-1;j>=0;--j)dp[i+1][j]=min(dp[i+1][j+1],dp[i+1][j]);
    }
    if(dp[n+1][0]==longinf)cout<<-1<<endl;
    else cout<<dp[n+1][0]<<endl;
    return 0;
}