#include<bits/stdc++.h>
using namespace std;
ifstream f("peste.in");
ofstream g("peste.out");
int n,k,t,i,j,s,c[1<<10];
long long dp[1<<16];
struct pt
{
    int x,y;
}a[1<<16];
bool cmp(pt x,pt y)
{
    if(x.x==y.x) return x.y<y.y;
    return x.x<y.x;
}
priority_queue<int,vector<int>,greater<int> >Q;
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,cmp);
    for(i=j=1;i<1001;++i)
    {
        for(;j<=n&&a[j].x<=i;++j) Q.push(a[j].y),s+=a[j].y;
        while((int)Q.size()>k) s-=Q.top(),Q.pop();
        c[i]=s;
    }
    for(i=1;i<=t;++i)
        for(j=1;j<=min(i,1000);++j)
            dp[i]=max(dp[i],dp[i-j]+c[j]);
    g<<dp[t];
}