using System;
using System.Linq;
using System.Numerics;
using System.Collections.Generic;
using System.IO;
using System.Text;

public class Solver
{
    public void Solve()
    {
        int n = ri;
        List<int> a = new List<int>();
        int m = 10000;
        for (int i = 0; i < n; i++)
        {
            a.Add(ri);
            if (a[i] < m)
            {
                m = a[i];
            }
        }
        long t = 0;
        int k = n;
        a.Remove(m);
        a.Sort();
        a.Reverse();
        List<string> s = new List<string>();
        if (m > 0)
        {
            if (n == 2)
            {
                s.Add($"{a[0]} {m}");
                t = a[0] - m;
            }
            else
            {
                s.Add($"{m} {a[0]}");
                t = m - a[0];
                a.RemoveAt(0);
                for (int i = 2; i < n - 1; i++)
                {
                    s.Add($"{t} {a[0]}");
                    t -= a[0];
                    a.RemoveAt(0);
                }
                s.Add($"{a[0]} {t}");
                t = a[0] - t;
            }
        }
        else if (a[0] >= 0)
        {
            if (n == 2)
            {
                s.Add($"{a[0]} {m}");
                t = a[0] - m;
            }
            else if (n == 3)
            {
                if (a[1] >= 0)
                {
                    s.Add($"{m} {a[1]}\r\n{a[0]} {m - a[1]}");
                    t = a[0] + a[1] - m;
                }
                else
                {
                    s.Add($"{a[0]} {a[1]}\r\n{a[0] - a[1]} {m}");
                    t = a[0] - a[1] - m;
                }
            }
            else if (a[1] >= 0)
            {
                s.Add($"{m} {a[1]}");
                t = m - a[1];
                a.RemoveAt(1);
                for (int i = 3; i < n; i++)
                {
                    if (a[1] < 0) { k = i; break; }
                    s.Add($"{t} {a[1]}");
                    t -= a[1];
                    a.RemoveAt(1);
                }
                s.Add($"{a[0]} {t}");
                t = a[0] - t;
                a.RemoveAt(0);
                for (int i = k; i < n; i++)
                {
                    s.Add($"{t} {a[0]}");
                    t -= a[0];
                    a.RemoveAt(0);
                }
            }
            else
            {
                s.Add($"{a[0]} {m}");
                t = a[0] - m;
                a.RemoveAt(0);
                for (int i = 2; i < n; i++)
                {
                    s.Add($"{t} {a[0]}");
                    t -= a[0];
                    a.RemoveAt(0);
                }
            }
        }
        else
        {
            s.Add($"{a[0]} {m}");
            t = a[0] - m;
            a.RemoveAt(0);
            for (int i = 2; i < n; i++)
            {
                s.Add($"{t} {a[0]}");
                t -= a[0];
                a.RemoveAt(0);
            }
        }
        Write(t);
        Write(string.Join("\r\n", s));
    }


    int ri { get { return sc.Integer(); } }
    long rl { get { return sc.Long(); } }
    double rd { get { return sc.Double(); } }
    string rs { get { return sc.Scan(); } }
    public StreamScanner sc = new StreamScanner(Console.OpenStandardInput());

    private const int mod = 1000000007;
    long Reverse(long n) { return Pow(n, mod - 2); }
    long Pow(long n, long p) { long t = n, q = 1; while (p > 0) { if (p % 2 == 1) { q = (q * t) % mod; } t = (t * t) % mod; p /= 2; } return q; }
    int PowUpper(int n, int b) { int p = 1; while (p <= n) { p *= b; } return p; }
    int Abs(int n) { return (n > 0) ? n : -n; }
    int Gcd(params int[] n) { int p = n[0]; for (int i = 1; i < n.Length; i++) { p = Gcd(p, n[i]); } return p; }
    int Gcd(int a, int b) { return (a == 0) ? b : Gcd(b % a, a); }
    int Lcm(params int[] n) { int p = n[0]; for (int i = 1; i < n.Length; i++) { p = Lcm(p, n[i]); } return p; }
    int Lcm(int a, int b) { return a * b / Gcd(a, b); }
    int Max(params int[] n) { int p = n[0]; for (int i = 1; i < n.Length; i++) { p = (p > n[i]) ? p : n[i]; } return p; }
    int Min(params int[] n) { int p = n[0]; for (int i = 1; i < n.Length; i++) { p = (p < n[i]) ? p : n[i]; } return p; }
    void Write<T>(T t) { Console.WriteLine(t.ToString()); }
    void YN(bool t) { Console.WriteLine(t ? "YES" : "NO"); }
    void Yn(bool t) { Console.WriteLine(t ? "Yes" : "No"); }
    void yn(bool t) { Console.WriteLine(t ? "yes" : "no"); }
}

static class Program
{
    static public void Main(string[] args)
    {
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        var solver = new Solver();
        solver.Solve();
        Console.Out.Flush();
    }
}

public class StreamScanner
{
    public StreamScanner(Stream stream) { str = stream; }
    private readonly Stream str;
    private readonly byte[] buf = new byte[1024];
    private int len, ptr;
    public bool isEof = false;
    public bool IsEndOfStream { get { return isEof; } }
    private byte read()
    {
        if (isEof) throw new EndOfStreamException();
        if (ptr >= len)
        {
            ptr = 0;
            if ((len = str.Read(buf, 0, 1024)) <= 0)
            {
                isEof = true;
                return 0;
            }
        }
        return buf[ptr++];
    }
    public char Char()
    {
        byte b = 0;
        do b = read();
        while (b < 33 || 126 < b);
        return (char)b;
    }
    public string Scan()
    {
        var sb = new StringBuilder();
        for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
            sb.Append(b);
        return sb.ToString();
    }
    public long Long()
    {
        long ret = 0; byte b = 0; var ng = false;
        do b = read();
        while (b != '-' && (b < '0' || '9' < b));
        if (b == '-') { ng = true; b = read(); }
        for (; true; b = read())
        {
            if (b < '0' || '9' < b)
                return ng ? -ret : ret;
            else ret = ret * 10 + b - '0';
        }
    }
    public int Integer() { return (int)Long(); }
    public double Double() { return double.Parse(Scan()); }
}


Measured memory_bytes: 38992