#include<bits/stdc++.h>
#define int long long
#define ull unsigned long long
#define ls(k) (k)<<1
#define rs(k) (k)<<1|1
#define debug(x) cout<<#x<<"="<<x<<endl
using namespace std;
const int inf=0x3f3f3f3f3f3f3f3f;
const int mod=0;
typedef pair<int,int> pii;
#define _ 5003
int preva[_],prew[_],prec[_],dp[10004];
pii it[_];
inline void subtask(){
    int n,w,k;cin>>n>>w>>k;
    for(int i=1;i<=n;i++) cin>>it[i].first>>it[i].second;
    sort(it+1,it+n+1,[](pii x,pii y){return x.second>y.second;});
    for(int i=1;i<=n;i++) preva[i]=preva[i-1]+it[i].second,prew[i]=prew[i-1]+it[i].first;
    priority_queue<int,vector<int>,greater<int>> q;
    int now=prew[k-1];
    for(int i=1;i<=k-1;i++) q.push(it[i].first);
    for(int i=k+1;i<=n;i++){
        if(!q.empty()&&it[i-1].first>q.top()){
            now-=q.top(),q.pop();
            now+=it[i-1].first;
            q.push(it[i-1].first);
        }
        prec[i]=prew[i]-(now+it[i].first);
    }
    memset(dp,-0x3f,sizeof(dp));
    dp[0]=0;
    int ans=0;
    for(int i=n;i>=k+1;i--){
        for(int j=w;j>=it[i].first;j--){
            dp[j]=max(dp[j],dp[j-it[i].first]+it[i].second);
        }
        int maxx=-inf;
        for(int j=0;j<=w-prec[i-1];j++) maxx=max(maxx,dp[j]);
        ans=max(ans,maxx+preva[i-1]);
    }
    cout<<ans;
}
signed main(){
    ios::sync_with_stdio(false);
    int t=1;//cin>>t;
    while(t--) subtask();
    return 0;
}

/*
5  20
9  10
3  5
10 1

*/