#include<cstdio>
long long q[1000001];
int n,i,j,k,s[1000000],d[1000000],r[1000001],p[1000001];
char t[9];

void A(int k,long long a,int b)
{if(k>n)
       A(s[k-n],2*a,b+1),A(d[k-n],2*a+1,b+1);
else
       p[k]=b,q[k]=a;}

int main()
{freopen("huffman.in","r",stdin);
freopen("huffman.out","w",stdout);
fgets(t,9,stdin);
for(j=0;t[j]!='\n';j++)
       n=n*10+(t[j]-'0');
for(i=1;i<=n;i++)
       {fgets(t,9,stdin),q[i]=1000001;
       for(j=0;t[j]!='\n';j++)
             r[i]=r[i]*10+(t[j]-'0');}
for(k=j=i=1;i<n;q[0]+=q[i++])
if(k<n&&r[k+1]<=q[j])
       q[i]=r[k]+r[k+1],s[i]=k++,d[i]=k++;
else
if(q[j+1]<=r[k]||k==n+1)
       q[i]=q[j]+q[j+1],s[i]=n+j++,d[i]=n+j++;
else
       q[i]=r[k]+q[j],s[i]=k++,d[i]=n+j++;
printf("%lld\n",q[0]),A(2*n-1,0,0);
for(i=1;i<=n;i++)
       printf("%d %lld\n",p[i],q[i]);
return 0;}