#include <stdio.h>
#include <set>
#include <vector>
#include <algorithm>

using namespace std;

#define NMAX 1024
#define SMAX 50002
#define pb push_back
#define sz size()
#define mp make_pair
#define ff first
#define ss second

long int a[NMAX];
long int d[SMAX];
long int n,i,j,k,T,Tm;
vector< pair<int, int> > v;
vector<int> v1;
long int x,y;

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

        scanf("%ld %ld %ld",&n,&k,&T);

        Tm=0;
        for (i=1;i<=n;i++)
                {
                scanf("%ld %ld",&x,&y);
                v.pb( mp(y,x) );
                Tm=max(y,Tm);
                }

        sort( v.begin(), v.end() );
        x=-1;
        v1.clear();
        for (i=0;i<=Tm;i++)
                {
                while ( (x<n-1)&&(v[x+1].ff==i) ) {
                                     x++;
                                     v1.pb( v[x].ss );
                                     }
                sort(v1.begin(), v1.end() );

                for (j=1;j<=k;j++)
                        {
                        if (j>v1.sz) break;
                        a[i]=a[i]+v1[ v1.sz - j ];
                        }
                }

        d[0]=0;
        for (i=1;i<=T;i++)
                {
                d[i]=0;
                for (j=min(i,Tm);j;j--)
                       d[i]=max(d[i],d[i-j]+a[j]);
                }
        printf("%ld",d[T]);
        return 0;
}