#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<climits>
#include<cstdlib>
#include<queue>
#include<cmath>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
template <typename T>
inline void read(T&x){
	int w = 0;x = 0;
	char ch = getchar();
	while(ch<'0' || ch>'9'){
		if(ch=='-') w = 1;
		ch = getchar();
	}
	while(ch>='0' && ch<='9'){
		x = (x<<1)+(x<<3)+(ch^48);
		ch = getchar();
	}
	if(w) x = ~x+1;
}
template <typename T,typename...Args>
inline void read(T&t,Args&...args){
	read(t);read(args...);
}
template <typename T>
inline T Min(T x,T y){ return (x < y ? x : y); }
template <typename T>
inline T Max(T x,T y){ return (x > y ? x : y); }
template <typename T>
inline T Abs(T x){ return (x < 0 ? ~x+1 : x); }
const int N = 5e3+10,M = 1e4+10;
int n,W,K;
struct node{
	int w; ll v;
	inline bool operator < (const node&G) const{
		return v > G.v;
	}
}g[N];
int vis[N],cnt;
ll dp[M],sumv;
int main(){
//	freopen("knapsack3.in","r",stdin);
	
	read(n,W,K);
	for(int i=1;i<=n;++i){
		read(g[i].w,g[i].v); 
		sumv += g[i].v;
	}
	sort(g+1,g+1+n);
//	for(int i=1;i<=n;++i) cout << g[i].w << " " << g[i].v << endl; cout << endl;
	for(int i=1;i<=n;++i){
		for(int j=W;j>=g[i].w;--j){
			dp[j] = Max(dp[j],dp[j-g[i].w]+g[i].v);
		}
	}
//	cout << dp[W] << endl;
	for(int i=1,tW=W;i<=n && tW>0;++i){
		for(int j=tW;j>=g[i].w;--j){
			if(dp[j]==dp[j-g[i].w]+g[i].v){
//				cout << j << " " << g[i].w << endl;
//				cout << i << endl << endl;	
				vis[i] = 1;
				++cnt;
				tW -= g[i].w;
				break;
			}
		}
	}
//	cout << cnt << endl;
	for(int i=1,tk=0;i<=n && tk<K;++i){
		if(vis[i]) continue;
		dp[W] += g[i].v;
		++tk;
	}

	printf("%lld",dp[W]);
	
	
	return 0;
}
/*
#1
4 10 1
9 10
10 1
3 5
5 20

#2
5 13 2
5 16
5 28
7 44
8 15
8 41
*/