//
//
//  Codeforces: ganariya
//  AtCoder: ganariya2525
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//include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <unordered_map>
#include <climits>
#include <set>
#include <unordered_set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <queue>
#include <random>
#include <complex>
#include <regex>
#include <locale>
#include <random>
#include <type_traits>
#include <chrono>

using namespace std;

#define SHOW_VECTOR(v) {std::cerr << #v << "\t:";for(const auto& xxx : v){std::cerr << xxx << " ";}std::cerr << "\n";}
#define SHOW_MAP(v){std::cerr << #v << endl; for(const auto& xxx: v){std::cerr << xxx.first << " " << xxx.second << "\n";}}

using LL = long long;

//~~~~~~~~~~~~~~~~~~~~~_(＾～＾ ｣ ∠)_~~~~~~~~~~~~~~~~~~~~~

int main() {

    int N;
    cin >> N;

    vector<LL> A(N);
    for (int i = 0; i < N; i++) cin >> A[i];
    sort(A.rbegin(), A.rend());

    vector<LL> plus, minus;
    plus.push_back(A[0]);
    for (int i = 1; i < N - 1; i++) {
        if (A[i] >= 0) plus.push_back(A[i]);
        else minus.push_back(A[i]);
    }
    minus.push_back(A[N - 1]);


    vector<pair<LL, LL >> methods;
    for (int i = 1; i < plus.size(); i++) {
        LL x = minus.back();
        LL y = plus[i];
        methods.push_back(make_pair(x, y));
        minus.back() -= y;
    }

    for (int i = 0; i < minus.size(); i++) {
        LL x = plus.front();
        LL y = minus[i];
        methods.push_back(make_pair(x, y));
        plus.front() -= y;
    }

    cout << plus.front() << endl;
    for(auto x: methods){
        cout << x.first << " " << x.second << endl;
    }

}






































Measured memory_bytes: 5872