#include <stdio.h>
#include <deque>
#define N 2000001
using namespace std;
typedef unsigned long long int UL;
int w[N],n;
UL cod[N];
UL niv[N];

struct nod
{int st,dr;
 UL w;
 nod (int a,int b,UL c)
 {st=a;
  dr=b;
  w=c;
 }
 nod(){}
}t[2*N];


void df(int poz,UL c,UL nivel)
{cod[poz]=c;
 niv[poz]=nivel;

 if(poz>n)
 {df(t[poz].st,c*2LL,nivel+1LL);
  df(t[poz].dr,c*2LL+1LL,nivel+1LL);
 }
}

int main ()
{freopen("huffman.in","r",stdin);
 freopen("huffman.out","w",stdout);
 int i,a,b,min;
 scanf("%d",&n);
 deque<int> qi;
 deque<int> qo;

 for (i=1;i<=n;i++)
 {scanf("%d",&w[i]);
  t[i]=nod(0,0,w[i]);
  qi.push_back(i);
 }
 
 while(qi.size()+qo.size()>1)
 {if(!qi.empty()&&!qo.empty())
  {if(t[qi.front()].w<t[qo.front()].w)
   {a=qi.front();qi.pop_front();
   }
   else
   {a=qo.front();qo.pop_front();
   }
  }
  else if(!qi.empty())
  {a=qi.front();qi.pop_front();
  }
  else if(!qo.empty())
  {a=qo.front();qo.pop_front();
  }

  if(!qi.empty()&&!qo.empty())
  {if(t[qi.front()].w<t[qo.front()].w)
   {b=qi.front();qi.pop_front();
   }
   else
   {b=qo.front();qo.pop_front();
   }
  }
  
  else if(!qi.empty())
  {b=qi.front();qi.pop_front();
  }
  else if(!qo.empty())
  {b=qo.front();qo.pop_front();
  }
  if(!qo.empty())
  {if(t[qo.back()].w>t[a].w+t[b].w)
   {printf("%d\n",qo.back());
    printf("%d\n\n",t[qo.back()].w);
   }
  // printf("jizz in my pants");
  }
  t[i]=nod(a,b,t[a].w+t[b].w);
  qo.push_back(i);
  i++;
 }
 
 i--;
 df(i,0,0);
 UL s=0;

 for (i=1;i<=n;i++)
 {s+=(UL)w[i]*(UL)niv[i];
 }
 
 printf("%lld\n",s);

 for (i=1;i<=n;i++)
 {printf("%lld %lld\n",niv[i],cod[i]);
 }
 
 return 0;
}