using System;
using System.Collections.Generic;
using System.Linq;
using static System.Console;
using static System.Convert;
using static System.Math;
//using Debug;
//using static System.Globalization.CultureInfo;
//using Edge = Pair<long, int>;
using System.Text;
class Program
{
    static void Main(string[] args)
    {
        Solve();
        //WriteLine(Solve());
    }
    static void Solve()
    {
        var num = Input.num;
        var ar = Input.ar.OrderBy(v=>v).ToArray();
        if(num==2)
        { WriteLine($"{ar[1] - ar[0]}\n{ar[1]} {ar[0]}");return; }
        var res = new List<string>(num - 1);
        var r = 0;
        if (ar[0] <= 0&&ar[num-1]>0)
        {
            r = ar[0];
            var i = num - 2;
            for(i=num-2;i>=0;i--)
            {
                if (ar[i] <= 0) break;
                res.Add($"{r} {ar[i]}");
                r -= ar[i];
            }
            res.Add($"{ar[num - 1]} {r}");
            r = -r + ar[num - 1];
            while (i-1 >= 0)
            {
                res.Add($"{r} {ar[i]}");
                r -= ar[i];
                i--;
            }
           
        }
        else if (ar[num - 1] <= 0)
        {
            r = ar[num - 1] - ar[0];
            res.Add($"{ar[num - 1]} {ar[0]}");
            for(var i=1;i<num-1;i++)
            {
                res.Add($"{r} {ar[i]}");
                r -= ar[i];
            }
        }
        else 
        {
            r = ar[0] - ar[num-1];
            res.Add($"{ar[0]} {ar[num-1]}");
            for (var i = 1; i < num - 2; i++)
            {
                res.Add($"{r} {ar[i]}");
                r -= ar[i];
            }
            res.Add($"{ar[num - 2]} {r}");
            r = -r + ar[num - 2];
        }
        WriteLine($"{r}\n{string.Join("\n", res)}");
    }
}

public class Input
{
    public static string read => ReadLine().Trim();
    public static int[] ar => read.Split(' ').Select(int.Parse).ToArray();
    public static int num => ToInt32(read);
    public static long[] arL => read.Split(' ').Select(long.Parse).ToArray();
    public static long numL => ToInt64(read);
    public static char[][] gred(int h)
        => Enumerable.Repeat(0, h).Select(_ => read.ToCharArray()).ToArray();
    public static int[] ar1D(int n)
        => Enumerable.Repeat(0, n).Select(_ => num).ToArray();
    public static long[] arL1D(int n)
        => Enumerable.Repeat(0, n).Select(_ => numL).ToArray();
    public static string[] strs(int n)
        => Enumerable.Repeat(0, n).Select(_ => read).ToArray();
    public static int[][] ar2D(int n)
        => Enumerable.Repeat(0, n).Select(_ => ar).ToArray();
    public static long[][] arL2D(int n)
        => Enumerable.Repeat(0, n).Select(_ => arL).ToArray();
    public static T getValue<T>(string g)
    {
        var t = typeof(T);
        if (t == typeof(int))
            return (T)(object)int.Parse(g);
        if (t == typeof(long))
            return (T)(object)long.Parse(g);
        if (t == typeof(string))
            return (T)(object)g;
        if (t == typeof(char))
            return (T)(object)char.Parse(g);
        if (t == typeof(double))
            return (T)(object)double.Parse(g);
        if (t == typeof(bool))
            return (T)(object)bool.Parse(g);
        return default(T);
    }
    public static string[] Make<T1, T2>(out T1 v1, out T2 v2)
    {
        var r = read.Split(' ');
        v1 = getValue<T1>(r[0]);
        v2 = getValue<T2>(r[1]);
        return r;
    }
    public static string[] Make<T1, T2, T3>(out T1 v1, out T2 v2, out T3 v3)
    {
        var r = Make(out v1, out v2);
        v3 = getValue<T3>(r[2]);
        return r;
    }
    public const long Inf = (long)1e18;
    public const double eps = 1e-6;
    public const string Alfa = "abcdefghijklmnopqrstuvwxyz";
    public const int MOD = 1000000007;
}


Measured memory_bytes: 43956