#!/bin/bash
read N
read v
while read line
do
  line=$((line*100000))
  if [[ -n $pre ]]; then
    pre=$(((line+pre)/2))
  else
    pre=$line
  fi
done <<EOF
  `echo $v | xargs -n1 echo | sort -n`
EOF
echo $((pre)) | \
sed -e 's/^\(.\{1\}\)/\1./'