#include <bits/stdc++.h>
using namespace std;
void Weapons19() {
  long long int n, k;
  cin >> n >> k;
  vector<long double> arr(n);
  long double left = 1000, right = 0;
  long double sum = 0;
  for (long long int i = 0; i < n; i++) {
    cin >> arr[i];
    left = min(left, arr[i]);
    right = max(right, arr[i]);
  }
  sort(arr.begin(), arr.end());
  vector<long double> pre(1, arr[0]);
  for (long long int i = 1; i < n; i++) {
    pre.push_back(pre.back() + arr[i]);
  }
  while (right - left > 0.000000001) {
    long double mid = (right + left) / 2.0;
    auto it = upper_bound(arr.begin(), arr.end(), mid);
    long long int ind = it - arr.begin();
    long double reqd = (mid * ind) - pre[ind - 1];
    long double avail = (pre[n - 1] - pre[ind - 1]) - ((n - ind) * mid);
    if ((avail * (100 - k)) / 100.0 < reqd) {
      right = mid;
    } else {
      left = mid;
    }
  }
  cout << left;
}
int32_t main() {
  cout << fixed << setprecision(16);
  cin.sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  Weapons19();
}
