input = gets.split(" ")
input.map!{|i| i.to_i}
input.sort!
input.delete_at(0)
input.delete_at(-1)
sum = 0
input.each do |j|
    sum += j
end
a = (sum.to_f / input.size).round(2).to_s# your code goes here
puts sprintf("%.2f",a)