#include <algorithm>
#include <vector>
#include <queue>
using namespace std;

#define DIM 50005
#define sc second
#define fs first
#define MAX 1005

long long bst[DIM],nr[MAX];
pair <int,int> v[DIM];
int n,k,t;

struct cmp
{
    bool operator () (const int &a,const int &b)
    {
        return a>b;
    }
}; priority_queue <int,vector <int>,cmp> h;

void read ()
{
    int i;

    scanf ("%d%d%d",&n,&k,&t);
    for (i=1; i<=n; ++i)
        scanf ("%d%d",&v[i].sc,&v[i].fs);
}

void solve ()
{
    long long sum;
    int i,j;

    sum=0;
    sort (v+1,v+n+1);
    for (i=j=1; i<MAX; ++i)
    {
        for ( ; j<=n && v[j].fs<=i; ++j)
        {
            sum+=v[j].sc;
            h.push (v[j].sc);
        }
        for ( ; (int)h.size ()>k; h.pop ())
            sum-=h.top ();
        nr[i]=sum;
    }
    for (i=1; i<=t; ++i)
        for (j=1; j<=min (i,MAX); ++j)
            bst[i]=max (bst[i],bst[i-j]+nr[j]);
    printf ("%lld",bst[t]);
}

int main ()
{
    freopen ("peste.in","r",stdin);
    freopen ("peste.out","w",stdout);

    read ();
    solve ();

    return 0;
}