var inpt = readLine()!.split(separator: " ").map{ Int($0)! * 100 }.sorted()
inpt.remove(at: 0)
inpt.remove(at: inpt.count-1)
let num = inpt.reduce(0, { $0 + $1 }) / inpt.count
var ans = "0.00"

if num <= 0 {
    // nanimosinai
} else if num < 10 {
    ans = "0.0\(num)"
} else if num < 100 {
    ans = "0.\(num)"
} else {
    ans = String(num)
    ans = ans.prefix(ans.count-2) + "." + ans.suffix(2)
}
print(ans)