program archim_rekurz;
var m,s : real;              { valos }
   i,z  : integer;           { egesz }
   n  : longint;           { hosszu egesz }
   
begin
   writeln(' A pi-t kozelitjuk');
   write(' Hany duplazas: ');
   readln(z);
   n:=6; m:=0.25;
   for i:=1 to z do
   begin
      m:=(1-sqrt(1-m))/2;
      n:=2*n;
      s:=n*sqrt(m);
      writeln(i:4,n:9,':  ',s:8:8);
   end;
end.