#include <stdio.h>
#define maxn 1000100
#define inf 1LL * 1000000000 * 1000000000

using namespace std;

struct nod{
    long long x;
    int f[2];
}nod[2*maxn];

int n, i, j, k, p, q[2][maxn], l[2], r[2], lg[maxn];
long long sol, cd[maxn], m;

void dfs(int poz, int cod, int level)
{
    if(nod[poz].f[0]){
        dfs(nod[poz].f[0], cod*2, level+1);
        dfs(nod[poz].f[1], cod*2+1, level+1);
    }else{
        lg[poz] = level;
        cd[poz] = cod;
    }
}

int main()
{
    freopen("huffman.in", "r", stdin);
    freopen("huffman.out", "w", stdout);
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i){
        scanf("%d", &nod[i].x);
        q[0][i] = i;
    }
    k = n;
    l[0] = l[1] = 1;
    r[0] = n;
    while(l[0]+l[1] <= r[0]+r[1]){
        ++k;
        for (j = 0; j < 2; ++j){
            p = 0;
            m = inf;
            for (i = 0; i < 2; ++i){
                if(l[i] <= r[i] && nod[q[i][l[i]]].x < m){
                    p = i;
                    m = nod[q[i][l[i]]].x;
                }
            }
            nod[k].f[j] = q[p][l[p]];
            nod[k].x += nod[q[p][l[p]]].x;
            ++l[p];
        }
        sol += nod[k].x;
        q[1][++r[1]] = k;
    }
    dfs(k, 0, 0);
    printf("%lld\n", sol);
    for (i = 1; i <= n; ++i)
        printf("%d %lld\n", lg[i], cd[i]);
    fclose(stdin);
    fclose(stdout);
    return 0;
}