#include<cstdio>
#define N 2000000
long long q[N];
int n,i,j,k,r[N],s[N],d[N],p[N];
int main()
{freopen("huffman.in","r",stdin);
freopen("huffman.out","w",stdout);
scanf("%d",&n);
for(i=1;i<=n;i++)
       scanf("%d",&r[i]),q[i]=N;
for(k=j=i=1;i<n;i++)
if(k<n&&r[k+1]<=q[j])
       q[i]=r[k]+r[k+1],s[i]=k++,d[i]=k++,q[0]+=q[i];
else
if(q[j+1]<=r[k]||k>n)
       q[i]=q[j]+q[j+1],s[i]=n+j++,d[i]=n+j++,q[0]+=q[i];
else
if(q[j]<=r[k]&&r[k]<=q[j+1])
       q[i]=r[k]+q[j],s[i]=k++,d[i]=n+j++,q[0]+=q[i];
else
       q[i]=r[k]+q[j],s[i]=n+j++,d[i]=k++,q[0]+=q[i];
printf("%lld\n",q[0]);
for(k=j=1,i=2*n-1,q[n-1]=0;k<=j;i=r[k++])
       p[s[i-n]]=p[d[i-n]]=p[i-n]+1,q[s[i-n]]=2*q[i-n],q[d[i-n]]=q[s[i-n]]+1,r[j++]=s[i-n],r[j++]=d[i-n];
for(i=1;i<=n;i++)
       printf("%d %lld\n",p[i],q[i]);
return 0;}