// Huffman cu doua cozi, O(n)

#include <stdio.h>

using namespace std;

#define maxn 1000100
#define inf 1LL * 1000000000 * 1000000000

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

long n, i, j, k, p, l[2], r[2];
long q[2][maxn], lg[maxn];
long long b[maxn], m, sol;

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

void solve() {
  k = n;
  l[0] = l[1] = 1;
  r[0] = n;
  while (l[0] + l[1] <= r[0] + r[1]) {
    ++k;
    for (j = 0; j < 2; j++) { // fiul
      p = 0;
      m = inf;
      //for (i = 0; i < 2; i++) { // coada
      if (l[0] <= r[0])
        m = nod[q[0][l[0]]].v;
      if (nod[q[1][l[1]]].v < m and l[1] <= r[1]) {
        p = 1;
        //m = nod[q[i][l[i]]].v;
      }
      //}
      //printf("%d\n", p);
      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);
}

int main() {
  freopen("huffman.in", "r", stdin);
  freopen("huffman.out", "w", stdout);
  scanf("%d", &n);
  for(i = 1; i <= n; i++) {
    scanf("%d", &nod[i].v);
    q[0][i] = i;
  }
  solve();
  printf("%lld\n", sol);
  for(i = 1; i <= n; i++) {
    printf("%d %lld\n", lg[i], b[i]);
  }
  return 0;
}