#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;

}