package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	in := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(in, &n)

	used := make([]bool, 3002)
	for i := 0; i < n; i++ {
		var x int
		fmt.Fscan(in, &x)
		if x <= 3001 {
			used[x] = true
		}
	}

	for i := 1; ; i++ {
		if !used[i] {
			fmt.Println(i)
			return
		}
	}
}