package main

import "fmt"

const MAX_N int = 2000

func main() {
    N := 6
    S := "ACDBCB"
    a := 0
    b := N-1

    for a <= b {
        left := false
        for i := 0; a+i < b; i++ {
            if S[a+i] < S[b-i] {
                left = true
                break
            } else if S[a+i] > S[b-i] {
                left = false
                break
            }
        }

        if left {
            fmt.Printf("%s",string(S[a]))
            a++
        } else {
            fmt.Printf("%s",string(S[b]))
            b--
        }
    }
    fmt.Printf("\n")
}