#include<bits/stdc++.h>
#define maxN 50005
using namespace std;
multiset<int> Set;
pair<int,int> v[maxN];
int x[1005],n,k,ttotal,nr,sum,dp[50005],maxim;
int main()
{
    freopen("peste.in","r",stdin);
    freopen("peste.out","w",stdout);
    scanf("%d%d%d",&n,&k,&ttotal);
    for(int i=1;i<=n;i++)
    {
        scanf("%d%d",&v[i].first,&v[i].second);
        swap(v[i].second,v[i].first);
    }
    sort(v+1,v+n+1);
    int ind=0;
    //x[i]-cea mai mare cantitate de peste care poate sa fie prinsa intr-un interval de lungime i
    //nr-numarul de elemente din Set
    //sum-suma elementelor din Set
    x[0]=0;
    for(int i=1;i<=n;i++)
    {
        Set.insert(v[i].second);
        sum+=v[i].second;
        if(Set.size()>k)
        {
            sum-=*Set.begin();
            Set.erase(Set.begin());
        }
        x[v[i].first]=sum;
    }
    for(int i=1;i<=v[n].first;i++)
    {
        x[i]=max(x[i],x[i-1]);
    }
    dp[0]=0;
    int m=v[n].first;
    for(int i=1;i<=ttotal;i++)
    {
        dp[i]=0;
        int minim=min(i-1,m);
        for(int j=1;j<=minim;j++)
        {
            dp[i]=max(dp[i],dp[i-j]+x[j]);
        }
    }
    printf("%d\n",dp[ttotal]);
    return 0;
}