#include <cstdio>
#include <queue>
using namespace std;

struct node{
    long long cost;
    int son[2];
}node[2000000];

int N, tag, numberOfBits[1000001], index;
long long decimalValue[1000001], textLength, maximum;
queue<int> Q[2];

void DFS(int tag, long long code, int level){

    if(node[tag].son[0]){
        DFS(node[tag].son[0], code * 2, level + 1);
        DFS(node[tag].son[1], code * 2 + 1, level + 1);
    }else{
        numberOfBits[tag] = level;
        decimalValue[tag] = code;
    }
}

int main(){

    freopen("huffman.in", "r", stdin);
    freopen("huffman.out", "w", stdout);

    scanf("%d", &N);

    for(int i = 1; i <= N; i++){
        scanf("%d", &node[i].cost);
        Q[0].push(i);
    }
    for(tag = N + 1;; tag++){
        for(int i = 0; i < 2; i++){
            index = 0; maximum = 1LL << 47;

            for(int j = 0; j < 2; j++){
                if(!Q[j].empty() && (node[Q[j].front()].cost < maximum)){
                    index = j;
                    maximum = node[Q[j].front()].cost;
                }
            }
            node[tag].son[i] = Q[index].front();
            node[tag].cost += node[Q[index].front()].cost;
            Q[index].pop();
        }
        textLength += node[tag].cost;
        Q[1].push(tag);

        if(Q[0].empty() && Q[1].size() == 1) break;
    }
    DFS(tag, 0, 0);
    printf("%lld\n", textLength);

    for(int i = 1; i <= N; i++){
        printf("%d %lld\n", numberOfBits[i], decimalValue[i]);
    }
    return 0;
}