#include <fstream>
#include <vector>
#include <deque>
using namespace std;

struct node
{
	node *left, *right;
	long long count;
	int idx;
	
	bool operator<(const node &other) const
	{
		return this->count < other.count;
	}

	bool operator>(const node &other) const
	{
		return this->count > other.count;
	}
};

int n;
vector<pair<int, long long> > res;
deque<node *> a, b;

long long df(node *n, int lg, long long cod)
{
	if(n->left == NULL)
	{
		res[n->idx] = make_pair(lg, cod);
		return 0;
	}
	else
	{
		cod = cod << 1;
		return n->count + df(n->left, lg + 1, cod) + df(n->right, lg + 1, cod + 1);
	}
}

inline node* pop(deque<node*> &a)
{
	node *tmp = a[0];
	a.pop_front();
	return tmp;
}

inline node* pop()
{
	if(a.size() == 0)
		return pop(b);
	if(b.size() == 0)
		return pop(a);
	if(a[0]->count <= b[0]->count)
		return pop(a);
	return pop(b);
}

int main()
{
	ifstream cin("huffman.in");
	ofstream cout("huffman.out");

	long long x;
	cin >> n;
	res.resize(n);
	a.resize(n);
	for(int i=0;i<n;++i)
	{
		cin >> x;
		node *n = new node;
		n->right = n->left = NULL;
		n->count = x;
		n->idx = i;
		a[i] = n;
	}

	long long count = 0;
	while(a.size() + b.size() > 1)
	{
		node *s = pop();
		node *d = pop();
		node *n = new node;
		n->count = s->count + d->count;
		n->left = s;
		n->right = d;
		b.push_back(n);
	}

	node *r = pop();

	cout << df(r, 0, 0) << endl;

	for(int i=0;i<n;++i)
		cout << res[i].first << " " << res[i].second << "\n";

	return 0;
}