program BackSQRT;
{$APPTYPE CONSOLE}
uses
  SysUtils;
var
 f,fout: Text;
 a:array[0..99999999] of extended;
 tmp: int64;
 count,j: 0..99999999;
begin
Count:=0;
assignfile(f,'input.txt');
reset(f);
while not Eof(f) do
  begin
  while not Eoln(f) do
      begin
      read(f,tmp);
      if tmp<0 then continue;
      a[count]:=tmp;
      inc(count);  // -1
      end;
  readln(f);
  end;
closefile(f);
assignfile(fout,'out.txt');
rewrite(fout);
for j:=count-1 downto 0 do writeln(fout,sqrt(a[j]):0:4);
closefile(fout);
end.

use standart input and output stream...