#include <bits/stdc++.h>
using namespace std;
long long MOD = 998244353;
double eps = 1e-7;
int n, k, a[10009];
int can(double m) {
  double dif = 0, over = 0;
  for (int i = 0; i < n; i++) {
    if (a[i] < m)
      dif += (m - a[i]);
    else
      over += (a[i] - m);
  }
  if (abs(over - dif / ((double)(100.0 - k) / 100.0)) <= eps)
    return 0;
  else if (over - dif / ((double)(100 - k) / 100) > 0) {
    return -1;
  }
  return 1;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> k;
  for (int i = 0; i < n; i++) cin >> a[i];
  if (n == 1) {
    cout << a[0];
    return 0;
  }
  sort(a, a + n);
  double l = a[0], r = a[n - 1], mid;
  for (int i = 0; i < 200; i++) {
    mid = (r + l) / 2;
    int st = can(mid);
    if (st == 0) {
      cout.precision(17);
      cout << mid << endl;
      break;
    } else if (st == 1) {
      r = mid;
    } else {
      l = mid;
    }
  }
  return 0;
}
