#include <bits/stdc++.h>
#include <boost/multiprecision/cpp_int.hpp>
using namespace std;

//#define int long long
//using ll = boost::multiprecision::cpp_int;
using ll = long long;
//constexpr int INF = 1e9;//INT_MAX=1<<31-1=2147483647
constexpr ll INF = (ll)1e18;//1<<63-1=9223372036854775807
constexpr ll MOD = (ll)1e9 + 7;
constexpr double EPS = 1e-9;
constexpr int dx[4]={1,0,-1,0};
constexpr int dy[4]={0,1,0,-1};
#ifdef LOCAL_ENV
	#define debug(var) std::cout<<#var" = "<<var<<std::endl
#else
	#define debug(var)
#endif
#define p(var) std::cout<<var<<std::endl
#define PI (acos(-1))
#define rep(i, n)   for(ll i=0, i##_length=(n); i< i##_length; ++i)
#define repeq(i, n) for(ll i=1, i##_length=(n); i<=i##_length; ++i)
#define all(a) (a).begin(), (a).end()
#define pb push_back
inline bool isnatural(double a) { return a>=0 && ceil(a)==floor(a); }
template<typename T> inline T power(T x, T n){ return n ? power(x*x%MOD,n/2)*(n%2?x:1)%MOD : 1; }
template<typename T> inline T gcd(T a, T b) { return b ? gcd(b,a%b) : a; }
template<typename T> inline T lcm(T a, T b) { return a / gcd(a,  b) * b; }
template<typename T1, typename T2>inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template<typename T1, typename T2>inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }
template<typename T1, typename T2> ostream& operator<<(ostream& s, const pair<T1, T2>& p) {return s << "(" << p.first << ", " << p.second << ")";}
template<typename T> ostream& operator<<(ostream& s, const vector<T>& v) {
	for (int i = 0, len = v.size(); i < len; ++i){
		s << v[i]; if (i < len - 1) s << "\t";
	}
	return s;
}
template<typename T> ostream& operator<<(ostream& s, const vector< vector<T> >& vv) {
	for (int i = 0, len = vv.size(); i < len; ++i){
		s << vv[i] << endl;
	}
	return s;
}
template<typename T1, typename T2> ostream& operator<<(ostream& s, const map<T1, T2>& m) {
	s << "{" << endl;
	for (typeof(m.begin()) itr = m.begin(); itr != m.end(); ++itr){
		s << "\t" << (*itr).first << " : " << (*itr).second << endl;
	}
	s << "}" << endl;
	return s;
}

/*-----8<-----8<-----*/

constexpr ll N_MAX = 100000;
constexpr ll A_I_MAX = 10000;

ll N;

vector<ll> a;
void input() {
	scanf("%lld", &N);
	a.assign(N,0);
	rep(i, N) cin>>a[i];
}

void solve() {



	ll t;
	//auto minit=min_element(a.begin(), a.end());
	sort(a.begin(), a.end());

	if(N==2){
		p(a[1]-a[0]);
		cout << a[1] << " " << a[0]<<endl;
		return;
	}


	//+だけ
	if(a[0]>=0){

		t=a[0]-a[1];
		for(ll i=2;i<N-1;i++){
			t=t-a[i];
		}
		cout<<a[N-1]-t<<endl;

		cout<<a[0]<<" "<<a[1]<<endl;
		t=a[0]-a[1];
		for(ll i=2;i<N-1;i++){
			cout<<t<<" "<<a[i]<<endl;
			t=t-a[i];
		}
		cout<<a[N-1]<<" "<<t<<endl;
		return;
	}else if(a[N-1]<0){
		//-のみ
		t=a[N-1];
		for(ll i=0;i<N-1;i++){
			a[N-1]-=a[i];
		}
		p(a[N-1]);
		a[N-1]=t;
		for(ll i=0;i<N-1;i++){
			cout<<a[N-1]<< " " <<a[i]<<endl;
			a[N-1]-=a[i];
		}
		return;		
	}




	//+-混在
	t=a[0];
	ll t1=a[N-1];
	for(ll i=1;i<N-1;i++){
		if(a[i]<0){
			a[N-1]-=a[i];
		}else{
			t-=a[i];
		}
	}
	cout<<a[N-1]-t<<endl;

	t=a[0];
	a[N-1]=t1;
	for(ll i=1;i<N-1;i++){
		if(a[i]<0){
			cout<<a[N-1]<<" "<<a[i]<<endl;
			a[N-1]-=a[i];
		}else{
			cout<<t<<" "<<a[i]<<endl;
			t-=a[i];
		}
	}
	cout<<a[N-1]<<" "<<t<<endl;
}

signed main() {
	input();
	solve();
	return 0;
}


Measured memory_bytes: 2688