#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N=5010;
int n,W,k;
ll f[10010];
ll ans;
ll suf[10010];
struct node{
    int w,v;
}a[N];
bool cmp(node x,node y){
    return x.w<y.w;
}
priority_queue <int,vector<int>,greater<int> > q;
int main(){
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    cin>>n>>W>>k;
    for(int i=1;i<=n;i++) cin>>a[i].w>>a[i].v;
    sort(a+1,a+1+n,cmp);
    ll sum=0;
    for(int i=n-k+1;i<=n;i++){
        sum+=a[i].v;q.push(a[i].v);
        suf[n-k+1]=sum;
    }
    for(int i=n-k;i>=1;i--){
        if(q.top()<a[i].v){
            sum-=q.top();sum+=a[i].v;
            q.push(a[i].v);
        }
        suf[i]=sum;
    }
    ans=max(ans,suf[1]);
    for(int i=1;i<=n-k;i++){
        for(int j=W;j>=a[i].w;j--)
            f[j]=max(f[j],f[j-a[i].w]+a[i].v);
        ans=max(ans,f[W]+suf[i+1]);
    }
    cout<<ans<<endl;
    return 0;
}