#include <bits/stdc++.h>
using namespace std;
long long a[2210], b[2210];
long long inf = 1e13;
int main() {
  memset(a, 0, sizeof(a));
  memset(b, 0, sizeof(b));
  int n = 0, k = 0;
  scanf("%d%d", &n, &k);
  for (int i = 1; i <= n; ++i) {
    scanf("%I64d", &a[i]);
  }
  for (int i = 1; i <= n; ++i) {
    scanf("%I64d", &b[i]);
  }
  long long l = 0, r = inf, res = 0;
  while (l <= r) {
    long long mid = (l + r) >> 1;
    priority_queue<long long, vector<long long>, greater<long long>> qa;
    priority_queue<long long> qb;
    long long sz = 0, cur = 0;
    for (int i = 1; i <= n; ++i) {
      qa.push(a[i]);
      long long tmp1 = qa.top() + b[i] - mid;
      long long tmp2 = qb.empty() ? inf : (b[i] - qb.top());
      if (tmp1 <= tmp2 && tmp1 <= 0) {
        cur += tmp1;
        ++sz;
        qb.push(b[i]);
        qa.pop();
      } else if (tmp2 < tmp1 && tmp2 < 0) {
        cur += tmp2;
        qb.pop();
        qb.push(b[i]);
      }
    }
    if (sz >= k) {
      res = cur + (long long)k * mid;
      r = mid - 1;
    } else {
      l = mid + 1;
    }
  }
  printf("%I64d", res);
  return 0;
}
