#include<fstream.h>
#define N 2000000
long long q[N];
long n,i,j,k,r[N],x[N],s[N],d[N],p[N];
int main()
{ifstream f("huffman.in");
ofstream g("huffman.out");
f>>n;
for(i=1;i<=n;i++)
       f>>p[i],q[i]=N,x[i]=i,r[i]=p[i],s[i]=d[i]=0;
j=k=1,q[0]=0;
for(i=1;i<n;i++)
       {if(k<=n)
                {if(p[k+1]<=q[j]&&k+1<=n)
                          q[i]=p[k]+p[k+1],s[i+n]=k,d[i+n]=k+1,k+=2;
                else
                          if(q[j+1]<=p[k])
                                    q[i]=q[j]+q[j+1],s[i+n]=j+n,d[i+n]=j+1+n,j+=2;
                          else
                                    if(q[j]<=p[k]&&p[k]<=q[j+1])
                                             q[i]=p[k]+q[j],s[i+n]=j+n,d[i+n]=k,j++,k++;
                                    else
                                             if(p[k]<=q[j]&&((q[j]<=p[k+1]&&k<n)||k+1>n))
                                                       q[i]=p[k]+q[j],s[i+n]=k,d[i+n]=j+n,j++,k++;}
       else
                q[i]=q[j]+q[j+1],s[i+n]=j+n,d[i+n]=j+1+n,j+=2;
       q[0]+=q[i],r[i+n]=q[i],x[i+n]=i+n;}
g<<q[0]<<"\n";
i=2*n-1,k=j=q[i]=p[i]=0,r[j++]=i;
while(k<j)
        {i=r[k++];
        if(s[i])
                 {p[x[s[i]]]=p[x[d[i]]]=p[x[i]]+1,q[x[s[i]]]=q[x[i]]<<1,q[x[d[i]]]=q[x[s[i]]]+1;
                 if(x[i]>n)
                          r[j++]=s[i],r[j++]=d[i];}}
for(i=1;i<=n;i++)
        g<<p[i]<<" "<<q[i]<<"\n";
return 0;}