var m,n,i,j:byte; s:string; pole:array[1..105]of string; begin readln(n); while n<>0 do if n=1 then begin writeln('Sheet 1, front: Blank, 1');writeln;readln(n);end else begin for i:=1 to n do begin str(i,s); pole[i]:=s;end; for i:=(n+1) to (n+5) do pole[i]:='Blank'; m:= (n+(n mod 4)); if n mod 4 = 0 then j:=n; if n mod 4 = 3 then j:=n+1; if n mod 4 = 2 then j:=n+2; if n mod 4 = 1 then j:=n+1; for i:=1 to (m div 2) do begin if i mod 2 = 0 then writeln('Sheet ',(((i-1) div 2)+1),', back : ',pole[0+i],', ',pole[m+1-i]) else writeln('Sheet ',(((i-1) div 2)+1),', front: ',pole[m+1-i],', ',pole[0+i]); end; writeln; readln(n); end; end.