#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
const int nmax=1000001;
int k;
long long sol,tot;
struct nod
{
    long long z;
    int st,dr,lvl;
}arb[2*nmax];
queue<int> Q,H;
int unite(int a,int b)
{
    arb[k].z=arb[a].z+arb[b].z;
    sol+=arb[k].z;
    arb[k].st=a;
    arb[k].dr=b;
    return k;
}
void dfs(int nod,int niv,long long cod)
{
    if(arb[nod].st!=0)
    {
        dfs(arb[nod].st,niv+1,cod*2);
    }
     if(arb[nod].dr!=0)
    {
        dfs(arb[nod].dr,niv+1,cod*2+1);
    }
    if(!arb[nod].dr && !arb[nod].st)
        {
            arb[nod].lvl=niv;
            arb[nod].z=cod;
        }
}
int main()
{
    freopen("huffman.in","r",stdin);
    freopen("huffman.out","w",stdout);
    int n,i,a,b,step1,step2;
    scanf("%d",&n);
    k=n+1;
    for(i=1;i<=n;++i)
    {
        scanf("%lld",&arb[i].z);
        Q.push(i);
    }
    sol=0;
    while(1)
    {
        step1=0;step2=0;
        if(Q.size()) step1=Q.front();
        if(H.size()) step2=H.front();
        if(step1==0)  {a=step2;H.pop();}
        else if(step2==0) {a=step1;Q.pop();}
        else if(arb[step1].z<=arb[step2].z) {a=step1;Q.pop();}
        else {a=step2;H.pop();}
        step1=0;step2=0;
        if(Q.size()) step1=Q.front();
        if(H.size()) step2=H.front();
        if(step1==0)  {b=step2;H.pop();}
        else if(step2==0) {b=step1;Q.pop();}
        else if(arb[step1].z<=arb[step2].z) {b=step1;Q.pop();}
        else {b=step2;H.pop();}
        H.push(unite(a,b));k++;
        if(Q.size()+H.size()<=1) break;
    }
    printf("%lld\n",sol);
    dfs(H.front(),0,0);
    for(i=1;i<=n;++i)
    {
        printf("%d %lld\n",arb[i].lvl,arb[i].z);
    }
}