#include <fstream>
#include <queue>

using namespace std;

ifstream in("huffman.in");
ofstream out("huffman.out");

const int N=1000001;

struct nod{
	int poz;
	long long val;
	nod *left,*right;
}*R;

int n,textsize,initial[N];
int code[N],length[N];
queue<nod *>Q1,Q2;

void Read(){
	int i;
	long long inputvalue;
	in>>n;
	for(i=1;i<=n;++i){
		in>>inputvalue;
		initial[i]=inputvalue;
		nod *aux;
		aux=new nod;
		aux->poz=i;
		aux->val=inputvalue;
		aux->left=NULL;
		aux->right=NULL;
		Q1.push(aux);
	}
}

/*inline nod* extractmin(){
	nod *aux;
	if(Q1.empty()){
		aux=Q2.front();
		Q2.pop();
		return aux;
	}
	if(Q2.empty()){
		aux=Q1.front();
		Q1.pop();
		return aux;
	}
	if(Q1.front()<Q2.front()){
		aux=Q1.front();
		Q1.pop();
		return aux;
	}
	else{
		aux=Q2.front();
		Q2.pop();
		return aux;
	}
}*/

inline nod* extractmin(){
	nod* minim=NULL;
	if(!Q1.empty())
		minim=Q1.front();
	if(!Q2.empty())
	{
		if(minim)
		{
			if(minim->val>Q2.front()->val)
				minim=Q2.front();
		}
		else
			minim=Q2.front();
	}
	if(!Q1.empty())
	{
		if(minim==Q1.front())
			Q1.pop();
		else
			Q2.pop();
	}
	else
		Q2.pop();
	return minim;
}


void Buildtree(){
	int i;
	nod *a,*b,*aux;
	for(i=1;i<n;i++){
		a=extractmin();
		b=extractmin();
		aux=new nod;
		aux->val=a->val+b->val;
		aux->poz=0;
		aux->left=a;
		aux->right=b;
		Q2.push(aux);
	}
	R=extractmin();
}

void Huffman(nod *a,int cod,int codesize){
	if(a->poz!=0){
		code[a->poz]=cod;
		textsize+=codesize*initial[a->poz];
		length[a->poz]=codesize;
		return;
	}
	Huffman(a->left,cod*2,codesize+1);
	Huffman(a->right,cod*2+1,codesize+1);
}
	
void Result(){
	int i;
	out<<textsize<<"\n";
	for(i=1;i<=n;i++){
		out<<length[i]<<" "<<code[i]<<"\n";
	}
}

int main(){
	Read();
	Buildtree();
	Huffman(R,0,0);
	Result();
	return 0;
}