#include<fstream>
#include<algorithm>
#include<queue>
#define plasa pair<int,int>
#define x first
#define y second

using namespace std;

const char iname[]="peste.in";
const char oname[]="peste.out";
const int maxn=50007;
const int maxt=1005;

ifstream f(iname);
ofstream g(oname);

int n,k,t,i,j,c[maxt],dp[maxn],s;
plasa a[maxn];
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);
    j=1;
    for(i=1;i<maxt;++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<maxt;++j)
        {
            dp[i]=max(dp[i],dp[i-j]+c[j]);
            if(i-j==0)
                break;
        }
    g<<dp[t]<<"\n";
}