#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,0);
	vector<int> B(N,0);
	for(int i=0;i<N;i++){
	    cin>>A[i];
	}
	
	for(int i=0;i<N;i++){
	    cin>>B[i];
	    
	}
	
	vector<int> diff(N,0);
	
	int old_sum = 0;
	
	for(int i=0;i<N;i++){
	    diff[i] = A[i]-B[i];
	    old_sum=old_sum+B[i];
	    
	    
	}
	
	sort(diff.rbegin() , diff.rend());
	
	int max_sum=0;
	
	
	for(int i=0;i<X;i++){
	 if(i<N-Y || diff[i]>0){
	    max_sum = max_sum + diff[i];
	 }
	
	}
	
	int new_sum = old_sum + max_sum;
	
	cout<<new_sum;
	
	
	
	

}