package chelper;

import java.util.ArrayList;
import java.util.List;

import io.InputReader;
import io.OutputWriter;
import misc.GCJSolution;
import misc.SimpleSavingChelperSolution;


public class TaskB extends GCJSolution {

  public void solve(int testNumber, InputReader in, OutputWriter out) {
    wrapSolve(testNumber, in, out);
  }

  @Override
  public void solve(int testNumber) {
    int n = in.nextInt();

    int k = in.nextInt();

    double[] a = in.nextDoubleArray(n);

    double dipVal = 0;
    
//    int removed = 0;
//
//    List<Double> vals = new ArrayList<>();
//
//    for (int i = 0; i < ; i++) {
//
//    }

    for (int i = 0; i < k + 1; i++) {
      double sum = 0;

      for (int j = 0; j < n; j++) {
        if (a[j] < dipVal) {
          sum += dipVal / n;
        } else {
          sum += a[j] / n;
        }
      }

      dipVal = sum;
    }

    out.println(dipVal);
  }
}