#include <stdio.h>
void print_for (int n, FILE *out)
{


    int nbSheets = (n/4);
    if( (n%4) != 0)
        nbSheets++;

    int sup=nbSheets*4,inf=1,i;



    fprintf(out,"Printing order for %d pages\n", n);

    for(i = 0; i < nbSheets; i++)
    {

        fprintf(out, "Sheet %d, front: ", i+1);
        if(sup > n)
            fprintf(out, "Blank");
        else
            fprintf(out, "%d",sup);
        fprintf(out, ", %d\n",inf);

        sup--;
        inf++;

        if(inf > n)
            break;
        fprintf(out, "Sheet %d, back: ", i+1);
        fprintf(out, "%d, ",inf);

        if(sup > n)
            fprintf(out, "Blank");
        else
            fprintf(out, "%d",sup);
        fprintf(out, "\n");
        sup--;
        inf++;

    }

}
int main ()
{
    int n;
    FILE *in = fopen("enum.in", "r");
    if(!in)
        return 1;
    FILE *out = fopen("enum.out", "w");
    if(!out)
        return 1;

    while(1){
        fscanf(in, "%d\n",&n);
        if(n == 0)
            break;
        print_for (n,out);
    }

    fclose (out);
    fclose (in);
    return 0;
}