#include <iostream>
#include <cstdio>
#define maxn 1000100
#define inf 1LL*1000000000*1000000000
using namespace std;
struct arbore
{
    int v;
    long f[2];
} H[2000100];
long n,p,l[2],r[2];
long q[2][maxn],lg[maxn];
long long b[maxn],m,sol;

int df(long poz, long cod, long nivel)
{
    if (H[poz].f[0])
    {
        df(H[poz].f[0],cod*2,nivel+1);
        df(H[poz].f[1],cod*2+1,nivel+1);
    }
    lg[poz]=nivel;
    b[poz]=cod;
}
int main()
{
    freopen("huffman.in","r",stdin);
    freopen("huffman.out","w",stdout);
    scanf("%lli",&n);
    int i;
    for (i=1;i<=n;i++)
    {
        scanf("%lli",&H[i].v);
        q[0][i]=i;
    }
    i=0;
    long k=n;
    l[0]=l[1]=1;
    r[0]=n;
    while(l[0]+l[1]<=r[0]+r[1])
    {
        ++k;
        for(long j=0;j<2;j++)
        {
            p=0;
            m=inf;
            for(long i=0;i<2;i++)
            {
                if(H[q[i][l[i]]].v<m && l[i]<=r[i])
                {
                    p=i;
                    m=H[q[i][l[i]]].v;
                }
            }
            H[k].f[j]=q[p][l[p]];
            H[k].v+=H[q[p][l[p]]].v;
            l[p]++;
        }
        sol+=H[k].v;
        q[1][++r[1]]=k;
    }
    df(k,0,0);
    printf("%lld\n", sol);
    for(long i=1;i<=n;i++)
        printf("%d %lld\n", lg[i], b[i]);
    return 0;
}