#include<iostream>
#include<algorithm>
#include<cstdio>
using namespace std;
struct list
{
int a;
int b;
};
bool cmp(list p,list q)
{
if((p.a-p.b)<=(q.a-q.b))
return 1;
else
return 0;
}
int main()
{
int n,k,l,i,j;
long long s;
list x[100002];
scanf("%d%d%d",&n,&k,&l);
for(i=0;i<n;i++)
scanf("%d",&x[i].a);
for(i=0;i<n;i++)
scanf("%d",&x[i].b);
sort(x,x+n,cmp);
/*for(i=0;i<n;i++)
printf("%d ",x[i].a);
printf("\n");
for(i=0;i<n;i++)
printf("%d ",x[i].b);
printf("\n");*/
s=0;
for(i=0;i<l;i++)
{
if(x[i].a<=x[i].b)
s=s+x[i].b;
else
if(n-i>k)
s=s+x[i].b;
else
break;
}
for(j=i;j<n;j++)
s=s+x[j].a;
printf("%lld\n",s);
return 0;
}

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MyAyIDEKNyA0IDkKNyAyIDM=

3 2 1
7 4 9
7 2 3