#include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
using namespace std;
using ll = long long;
using vec = vector<ll>;
using vect = vector<double>;
using Graph = vector<vector<ll>>;
#define loop(i, n) for (ll i = 0; i < n; i++)
#define Loop(i, m, n) for (ll i = m; i < n; i++)
#define pool(i, n) for (ll i = n; i >= 0; i--)
#define Pool(i, m, n) for (ll i = n; i >= m; i--)
#define mod 1000000007ll
#define flagcount __builtin_popcount
#define flag(x) (1 << x)
#define flagadd(bit, x) bit |= flag(x)
#define flagpop(bit, x) bit &= ~flag(x)
#define flagon(bit, i) bit &flag(i)
#define flagoff(bit, i) !(bit & (1 << i))
#define all(v) v.begin(), v.end()
#define low2way(v, x) lower_bound(all(v), x)
#define high2way(v, x) upper_bound(all(v), x)
#define idx_lower(v, x) (distance(v.begin(), low2way(v, x)))  //配列vでx未満の要素数を返す
#define idx_upper(v, x) (distance(v.begin(), high2way(v, x))) //配列vでx以下の要素数を返す
#define idx_lower2(v, x) (v.size() - idx_lower(v, x))         //配列vでx以上の要素数を返す
#define idx_upper2(v, x) (v.size() - idx_upper(v, x))         //配列vでxより大きい要素の数を返す
#define putout(a) cout << a << endl
#define Gput(a, b) G[a].push_back(b)
#define Sum(v) accumulate(all(v), 0ll)
#define gcd(x, y) __gcd(x, y)
ll ctoi(char c)
{
    if (c >= '0' && c <= '9')
    {
        return c - '0';
    }
    return 0;
}
template <typename T>
T lcm(T x, T y)
{
    T z = gcd(x, y);
    return x * y / z;
}
template <typename T>
bool primejudge(T n)
{
    if (n < 2)
        return false;
    else if (n == 2)
        return true;
    else if (n % 2 == 0)
        return false;
    double sqrtn = sqrt(n);
    for (T i = 3; i < sqrtn + 1; i++)
    {
        if (n % i == 0)
        {
            return false;
        }
        i++;
    }
    return true;
}
//場合によって使い分ける
//const ll dx[4]={1,0,-1,0};
//const ll dy[4]={0,1,0,-1};
const ll dx[8] = {1, 1, 0, -1, -1, -1, 0, 1};
const ll dy[8] = {0, 1, 1, 1, 0, -1, -1, -1};
//2次元配列の宣言
//vector<vector<ll>> field(h, vector<ll>(w));

int main()
{
    cout << fixed << setprecision(30);
    ll n;
    cin >> n;
    vec a(n);
    loop(i, n) cin >> a[i];
    sort(all(a));
    vec x(n - 1), y(n - 1);
    ll M;
    //負の数がない場合
    if (a[0] >= 0)
    {
        ll lownum = a[0];
        loop(i, n - 2)
        {
            x[i] = lownum;
            y[i] = a[i + 1];
            lownum -= a[i + 1];
        }
        x[n - 2] = a[n - 1];
        y[n - 2] = lownum;
        M = x[n - 2] - y[n - 2];
        putout(M);
        loop(i, n - 1) cout << x[i] << " " << y[i] << endl;
    }
    //負の数がある場合
    else
    {
        ll highzero = -1;
        loop(i, n) if (a[i] >= 0)
        {
            highzero = i;
            break;
        }
        if (highzero == -1)
        {
            ll highnum = a[n - 1];
            loop(i, n - 1)
            {
                x[i] = highnum;
                y[i] = a[i];
                highnum -= a[i];
            }
            putout(highnum);
            loop(i, n - 1) cout << x[i] << " " << y[i] << endl;
            return 0;
        }
        ll lownum = a[0];
        ll count = 0;
        Loop(i, highzero, n - 1)
        {
            x[count] = lownum;
            y[count] = a[i];
            lownum -= a[i];
            count++;
        }
        ll highnum = a[n - 1];
        Loop(i, 1, highzero)
        {
            x[count] = highnum;
            y[count] = a[i];
            highnum -= a[i];
            count++;
        }
        x[n - 2] = highnum;
        y[n - 2] = lownum;
        M = x[n - 2] - y[n - 2];
        putout(M);
        loop(i, n - 1) cout << x[i] << " " << y[i] << endl;
    }
    return 0;
}


Measured memory_bytes: 5612