#include <bits/stdc++.h>
const long double eps = 1e-7;
const double pi = acos(-1.0);
const long long inf = 1e18;
using namespace std;
int n, k, a[11111];
double ans = 0;
bool fun(double val) {
  double sum1 = 0, sum2 = 0;
  for (int i = 0; i < n; i++) {
    if (1.0 * a[i] > val) {
      sum1 += (1 - 1.0 * k / 100) * (a[i] - val);
    } else
      sum2 += val - a[i];
  }
  if (sum1 >= sum2) return true;
  return false;
}
void bin(double ll, double rr) {
  if (ll + eps > rr) {
    ans = 1.0 * (ll + rr) / 2;
    return;
  }
  double xx = 1.0 * (ll + rr) / 2;
  if (fun(xx) == true)
    bin(xx, rr);
  else
    bin(ll, xx);
}
int main(int argc, const char* argv[]) {
  cin >> n >> k;
  for (int i = 0; i < n; i++) cin >> a[i];
  bin(0.0, 1000.0);
  cout << fixed << setprecision(7) << ans;
  return 0;
}
