#include <bits/stdc++.h>
const long long M = 100000000;
using namespace std;
int n, k;
bool ok(long long);
long long a[10000 + 5], ans, sm = 0;
long long mx;
int main() {
  scanf("%d %d", &n, &k);
  for (int i = 0; i < n; ++i) {
    scanf("%d", a + i);
    a[i] *= M;
    sm += a[i];
  }
  mx = sm / n;
  long long l = 0, r = mx, mid = l + (r - l) / 2;
  while (r > l) {
    if (mid == l) {
      if (ok(r)) {
        mid = r;
      }
      break;
    }
    if (ok(mid)) {
      l = mid;
    } else {
      r = mid - 1;
    }
    mid = l + (r - l) / 2;
  }
  printf("%0.12f\n", mid / (M * 1.0));
}
bool ok(long long mid) {
  long long p_in = sm;
  long long p_loss = 0;
  for (int i = 0; i < n; ++i) {
    if (a[i] > mid) p_loss += (a[i] - mid) * ((k) / 100.0);
  }
  long long p_out = n * mid;
  return (p_in - p_loss >= p_out);
}
