package main

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

func main() {
	reader := bufio.NewReader(os.Stdin)
	var n int
	fmt.Fscan(reader, &n)
	var s string
	fmt.Fscan(reader, &s)

	res := make([]byte, 0, n)
	for i := 0; i < len(s); i++ {
		if len(res)%2 == 0 || s[i] != res[len(res)-1] {
			res = append(res, s[i])
		}
	}
	if len(res)%2 != 0 {
		res = res[:len(res)-1]
	}

	fmt.Println(n - len(res))
	fmt.Println(string(res))
}