#include <stdio.h>
#define Inf 8000000000000000000LL
#define N 1000010

short lung[N];
long long val[N],lg=0;
long long k[N<<1],t1,t2;
int h[N<<1],n;

inline void huff (int c,int u,long long v)
{
    if (c<n) {
        lung[c]=u;
        val[c]=v;
        return;
    }
    c-=n;
    huff (h[c<<1],u+1,v<<1);
    huff (h[(c<<1)+1],u+1,(v<<1)+1);
}

int main () {
    freopen ("huffman.in","r",stdin);
    freopen ("huffman.out","w",stdout);
    int i,c1=0,c2,d2,c=2;
    scanf ("%d",&n);
    c2=d2=n+1;
    for (i=0; i<n; i++) scanf ("%lld",k+i);
    for (; i<=n<<1; i++) k[i]=Inf;
    while (1) {
        if (k[c1]<=k[c2]) {
            h[c++]=c1;
            t1=k[c1++];
        }
        else {
            h[c++]=c2;
            t1=k[c2++];
        }
        if (k[c1]<=k[c2]) {
            h[c++]=c1;
            t2=k[c1++];
        }
        else {
            h[c++]=c2;
            t2=k[c2++];
        }
        if (t2==Inf) break;
        lg+=t1+t2;
        k[d2++]=t1+t2;
    }
    huff (c-3,0,0);
    printf ("%lld\n",lg);
    for (i=0; i<n; i++) printf ("%d %lld\n",lung[i],val[i]);
    fclose (stdin); fclose (stdout);
    return 0;
}