#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
	int n,x,y;cin>>n>>x>>y;
	vector<int>a(n),b(n),diff(n);
	for(int i=0;i<n;i++){
	    cin>>a[i];
	}
	int old_sum=0;
	for(int i=0;i<n;i++){
	    cin>>b[i];
	    old_sum+=b[i];
	    diff[i]=a[i]-b[i];
	    
	}
	int a_count=1,Optimal_diff=0;
	sort(diff.begin(),diff.end());
	while(a_count<=x){
	    int temp=0;
	    if(n-a_count>y){
	        a_count++;
	        continue;
	    }
	    for(int j=0;j<a_count;j++){
	        temp+=diff[n-1-j];
	    }
	    Optimal_diff=max(temp,Optimal_diff);
	    
	    a_count++;
	    
	}
	
	
	cout<<Optimal_diff+old_sum<<endl;
	

}