#include <iostream>
#include <cstdio>

using namespace std;

const int NMAX = 1000000 + 100;
const long long INF = 1LL * 1e18;

struct Tree {
  long long v;
  int son[2];
};

int n;
int q[2][1 + NMAX];
int len[1 + NMAX];
long long no[1 + NMAX];
long long res;
Tree arb[1 + 2 * NMAX];

void dfs(int pos, long long code, int level) {
    if(arb[pos].son[0] != 0) {
      dfs(arb[pos].son[0], code * 2, level + 1);
      dfs(arb[pos].son[1], code * 2 + 1, level + 1);
        return;
    }
    len[pos] = level;
    no[pos] = code;
}

void solve() {
  int l[2] = {1, 1};
  int r[2] = {n, 0};
  int x = n;

  int i, j;
  while(l[0] + l[1] <= r[0] + r[1]) {
    x++;
    for(i = 0; i <= 1; i++) {
      int p = 0;
      long long sz = INF;
      for(j = 0; j <= 1; j++) {
        if(arb[q[j][l[j]]].v < sz && l[j] <= r[j]) {
          p = j;
          sz = arb[q[j][l[j]]].v;
        }
      }
      arb[x].son[i] = q[p][l[p]];
      arb[x].v += arb[q[p][l[p]]].v;
      l[p]++;
    }
    res += arb[x].v;
    q[1][++r[1]] = x;
  }
  dfs(x, 0, 0);
}

int main()
{
  freopen("huffman.in", "r", stdin);
  freopen("huffman.out", "w", stdout);
  scanf("%d", &n);

  for(int i = 1; i <= n; i++) {
    scanf("%d", &arb[i].v);
    q[0][i] = i;
  }

  solve();

  printf("%lld\n", res);
  for(int i = 1; i <= n; i++) {
    printf("%d %lld\n", len[i], no[i]);
  }

  return 0;
}