#include <fstream>
#include <cstring>
#include <cstdio>
#define INF 0x3f3f3f3f
#define NMAX 1000003
using namespace std;

ifstream fin ("huffman.in"); ofstream fout ("huffman.out");

long n, p, l[2], r[2];
long q[2][NMAX], lg[NMAX];
long long b[NMAX], m, sol;

struct nod
{
	long long v;
	long f[2];
} nod[2 * NMAX];

void ReadData ()
{
	fin >> n;
	for (int i = 1; i <= n; ++i)
	{
		fin >> nod[i].v;
		q[0][i] = i;
	}
}

void DF (long poz, long long cod, long nivel)
{
	if (nod[poz].f[0])
	{
		DF (nod[poz].f[0], 2 * cod, nivel + 1);
		DF (nod[poz].f[1], 2 * cod + 1, nivel + 1);
	}
	lg[poz] = nivel;
	b[poz] = cod;
}

void Solve ()
{
	int k = n;
	l[0] = l[1] = 1;
	r[0] = n;
	while (l[0] + l[1] <= r[0] + r[1])
	{
		++k;
		for (int j = 0; j < 2; ++j)
		{
			p = 0;
			m = INF;
			for (int i = 0; i < 2; ++i)
			{
				if (nod[q[i][l[i]]].v < m && l[i] <= r[i])
				{
					p = i;
					m = nod[q[i][l[i]]].v;
				}
			}
			nod[k].f[j] = q[p][l[p]];
			nod[k].v += nod[q[p][l[p]]].v;
			l[p]++;
		}
		sol += nod[k].v;
		q[1][++r[1]] = k;
	}
	DF (k, 0, 0);
}

void WriteData ()
{
	fout << sol << "\n";
	for (int i = 1; i <= n; ++i)
		fout << lg[i] << " " << b[i] << "\n";
}

int main ()
{
	ReadData ();
	Solve ();
	WriteData ();
	fin.close (); fout.close ();
	return 0;
}