#!/bin/bash

read s

sum=0
maxi=-1
mini=1000
for x in $s; do
	sum=$((sum + x))
	if [ $x -gt $maxi ]; then
		maxi=$x
	fi
	if [ $x -lt $mini ]; then
		mini=$x
	fi
done
sum=$((sum-maxi-mini))

ave=`echo $sum | awk '{printf("%.2f", $1/4.0);}'`
echo $ave