package main import . "fmt" import . "os" import bf "bufio" func main() { rd:=bf.NewReader(Stdin) var n int Fscan(rd,&n) a := make([]int, 3e3+1) for i := 0; i < n; i++ { var v int Fscan(rd,&v) a[v]++ } b := make([]int,3e3+1) for i:=0; i