#include<fstream>
using namespace std;
#define NMAX 1000005
ifstream fin("huffman.in");
ofstream fout("huffman.out");
struct nod
{
    long long v;
    int f[2];
} A[NMAX<<1];
int n,k,dh,B[NMAX];
long long lg,C[NMAX],H[NMAX<<1];
inline void inters(long long &a, long long &b)
{
    long long aux=a;
    a=b, b=aux;
}
inline int extrage_min()
{
    int x,y,r=H[1];
    inters(H[1],H[dh--]);
    x=1;
    while (2*x<=dh)
    {
        y=2*x;
        if (y<dh && A[H[y]].v>A[H[y+1]].v)
            ++y;
        if (A[H[x]].v>A[H[y]].v)
            inters(H[x],H[y]);
        else
            break;
        x=y;
    }
    return r;
}
inline void introduce(int &val)
{
    int x,y;
    H[++dh]=val;
    for (x=dh;x>1;x>>=1)
    {
        y=x>>1;
        if (A[H[x]].v<A[H[y]].v)
            inters(H[x],H[y]);
        else
            break;
    }
}
void actualizare(int nod, int x, long long y)
{
    int i;
    if (nod>n)
        for (i=0;i<2;++i)
            actualizare(A[nod].f[i],x+1,(y<<1)+i);
    else
        B[nod]=x, C[nod]=y;
}
int main()
{
    int i,x,y;
    fin>>n;
    for (i=1;i<=n;++i)
    {
        fin>>A[i].v;
        H[i]=i;
    }
    dh=n;
    for (k=n+1;k<2*n;++k)
    {
        x=extrage_min();
        y=extrage_min();
        A[k].f[0]=x, A[k].f[1]=y;
        A[k].v=A[x].v+A[y].v;
        lg+=A[k].v;
        introduce(k);
    }
    fout<<lg<<"\n";
    actualizare(2*n-1,0,0);
    for (i=1;i<=n;++i)
        fout<<B[i]<<" "<<C[i]<<"\n";
    return 0;
}