using System;
using System.Collections.Generic;
using System.Linq;

namespace test
{
    class Program
    {
        static void Main(string[] args)
        {
            var N = ReadLong();
            var A = ReadArrayLong();
            var plus = new List<long>();
            var minus = new List<long>();
            for (int i = 0; i < N; i++)
            {
                if (A[i] >= 0) plus.Add(A[i]);
                else minus.Add(A[i]);
            }
            plus.Sort();
            minus.Sort();
            if (N == 2)
            {
                if (plus.Count() == 0)
                {
                    Console.WriteLine(minus[1] - minus[0]);
                    Console.WriteLine(minus[1] + " " + minus[0]);
                }
                else if (minus.Count() == 0)
                {
                    Console.WriteLine(plus[1] - plus[0]);
                    Console.WriteLine(plus[1] + " " + plus[0]);
                }
                else
                {
                    Console.WriteLine(plus[0] - minus[0]);
                    Console.WriteLine(plus[0] + " " + minus[0]);
                }
                return;
            }
            var pQue = new Queue<long>();
            var mQue = new Queue<long>();
            var ans = new List<long[]>();
            if (minus.Count() == 0)
            {
                ans.Add(new long[] { plus[0], plus[plus.Count() - 1] });
                mQue.Enqueue(plus[0] - plus[plus.Count() - 1]);
                for (int i = 1; i < plus.Count() - 1; i++) pQue.Enqueue(plus[i]);
            }
            else if (plus.Count() == 0)
            {
                ans.Add(new long[] { minus[minus.Count() - 1], minus[0] });
                pQue.Enqueue(minus[minus.Count() - 1] - minus[0]);
                for (int i = 1; i < minus.Count() - 1; i++) mQue.Enqueue(minus[i]);
            }
            else
            {
                for (int i = 0; i < plus.Count(); i++) pQue.Enqueue(plus[i]);
                for (int i = 0; i < minus.Count(); i++) mQue.Enqueue(minus[i]);
            }
            while (pQue.Any() || mQue.Any())
            {
                if (pQue.Count() == 1 && mQue.Count() == 1)
                {
                    var p = pQue.Dequeue();
                    var m = mQue.Dequeue();
                    ans.Add(new long[] { p, m });
                    Console.WriteLine(p - m);
                }
                else if (pQue.Count() >= mQue.Count())
                {
                    var p = pQue.Dequeue();
                    var m = mQue.Dequeue();
                    ans.Add(new long[] { m, p });
                    mQue.Enqueue(m - p);
                }
                else
                {
                    var p = pQue.Dequeue();
                    var m = mQue.Dequeue();
                    ans.Add(new long[] { p, m });
                    pQue.Enqueue(p - m);
                }
            }

            foreach (var a in ans) Console.WriteLine(a[0] + " " + a[1]);

            Console.WriteLine();
            Console.ReadLine();
        }

        static string Read() { return Console.ReadLine(); }
        static int ReadInt() { return int.Parse(Read()); }
        static long ReadLong() { return long.Parse(Read()); }
        static int[] ReadArrayInt() { return Read().Split(' ').Select(s => int.Parse(s)).ToArray(); }
        static long[] ReadArrayLong() { return Read().Split(' ').Select(s => long.Parse(s)).ToArray(); }
    }
}

Measured memory_bytes: 35928