#include <iostream>
#include <fstream>
#define DIM 50005
#include <algorithm>
using namespace std;
ifstream f("peste.in");
ofstream g("peste.out");
struct peste
{
    int p,t;
}a[DIM];
int timp,n,k,d[DIM],cost[DIM],sol[DIM];
void read()
{
    f>>n>>k>>timp;
    for(int i=1;i<=n;i++)
        f>>a[i].p>>a[i].t;
    f.close();
}
inline bool cmp(peste a,peste b){if(a.t==b.t)return a.p>b.p; return a.t<b.t;}
void solve()
{
    sort(a+1,a+n+1,cmp);
    int j=1,s=0,head=1,tail=0;
    for(int i=1;i<=n;i++)
    {
        d[++tail]=a[i].p;
        s+=a[i].p;
        if(tail-head+1>k)
        {
            s-=d[head];
            ++head;
        }
        cost[a[i].t]=s;
    }
    for(int i=1;i<=a[n].t;i++)
        cost[i]=max(cost[i-1],cost[i]);
    for(int i=1;i<=timp;i++)
         for(j=1;j<=min(i,a[n].t);++j)
            sol[i]=max(sol[i],sol[i-j]+cost[j]);
    g<<sol[timp];
}
int main()
{
    read();
    solve();
    return 0;
}