import core.bitop, std.algorithm, std.ascii, std.bigint, std.conv, std.math,
    std.functional, std.numeric, std.range, std.stdio, std.string, std.random,
    std.typecons, std.container, std.format;
static import std.ascii;

// dfmt off
T lread(T = long)(){return readln.chomp.to!T();}
T[] aryread(T = long)(){return readln.split.to!(T[])();}
void scan(TList...)(ref TList Args){auto line = readln.split();
foreach (i, T; TList){T val = line[i].to!(T);Args[i] = val;}}
alias sread = () => readln.chomp();enum MOD = 10 ^^ 9 + 7;
alias PQueue(T, alias less = "a<b") = BinaryHeap!(Array!T, less);
// dfmt on

void main()
{
    long N = lread();
    auto A = aryread();
    A.sort();
    long x = () {
        long ok = 0;
        long ng = N;
        while (1 < ng - ok)
        {
            long m = (ok + ng) / 2;
            if (A[m] < 0)
            {
                ok = m;
            }
            else
            {
                ng = m;
            }
        }
        if (ok == N - 1)
            ok = N - 2;
        return ok;
    }();
    // writeln(A);
    // writeln(x);
    writeln(A[x + 1 .. N].sum() - A[0 .. x + 1].sum());
    long a = A[0];
    foreach (i; x + 1 .. N - 1)
    {
        writefln("%s %s", a, A[i]);
        a = a - A[i];
    }
    writefln("%s %s", A[N - 1], a);
    long b = A[N - 1] - a;
    foreach (i; 1 .. x + 1)
    {
        writefln("%s %s", b, A[i]);
        b = b - A[i];
    }
}
