#include<bits/stdc++.h>
using namespace std;
ifstream f("peste.in");
ofstream g("peste.out");
int n,k,t,i,j,s;
long long c[1<<10],dp[1<<16];
struct pt
{
    int x,y;
}a[1<<16];
priority_queue<int,vector<int>,greater<int> >H;
int main()
{
    f>>n>>k>>t;
    for(i=1;i<=n;++i) f>>a[i].y>>a[i].x;
    sort(a+1,a+n+1);
    for(i=j=1;i<1001;++i)
    {
        for(;j<=n&&a[j].x<=i;++j)
            H.push(a[j].y),s+=a[j].y;
        while((int)H.size()>k) s-=H.top(),H.pop();
        c[i]=s;
    }
    for(i=1;i<=t;++i)
        for(j=1;j<=i;++j)
            dp[i]=max(dp[i],dp[i-j]+c[j]);
    g<<dp[t];
}