#include <iostream>
#include <queue>
#define int long long
using namespace std;
const int nmax = 3e5 + 7;
int v[nmax], b[nmax];
struct pairing {
int first, second;
const bool operator < (pairing a) const {
if(first != a.first) {
return first > a.first;
} else {
return second > a.second;
}
}
};
int32_t main() {
int n, k;
cin >> n >> k;
for(int i = 1; i <= n; i ++) {
cin >> v[i];
}
for(int i = 1; i <= n; i ++){
cin >> b[i];
}
priority_queue<pairing> pq;
for(int i = 1; i <= n; i ++) {
pq.push({max(v[i], b[i]), i});
}
for(int i = 2; i <= k; i ++) {
for(int j = 1; j <= n; j ++) {
int sum = pq.top().first, ind = pq.top().second;
pq.pop();
if(j == ind) {
sum += max(v[j], b[j]);
} else {
sum += b[ind];
}
pq.push({sum, ind});
}
}
int minn = 1e18;
while(!pq.empty()) {
minn = min(minn, pq.top().first);
pq.pop();
}
cout << minn;
return 0;
}
