#include <iostream>
#include <vector>

using namespace std;

int main (){
  
  while (true){
    int n, k;
    cin >> n >> k;

    if (n == 0 && k == 0) break;

    vector<int> a (n);
    vector<int> b (n);
    for (int i = 0; i < n; i++) cin >> a[i];
    for (int i = 0; i < n; i++) cin >> b[i];
    
    double left = 0;
    double right = 1;
    while (right-left > 1e-10){
      double x = (left+right)/2;

      vector<double> v;
      for (int i = 0; i < n; i++) v.push_back (a[i] - x*b[i]);
      sort (v.begin(), v.end());
      
      double sum = 0;
      for (int i = k; i < n; i++) sum += v[i];
      if (sum >= 0) left = x;
      else right = x;      
    }
    
    cout << (int)(100*(left+right)/2 + 0.5) << endl;
  }
}