Program P2;
{--------------------------------------------------------------
  Se dau 2 nr reale a si e (e>0.1).
  Sa se calculeze sqrt(a) cu exactitatea e (fara a utiliza sqrt).
 --------------------------------------------------------------}
var 
   a, e: real;
   ex: byte;
{--------------------------------------------------------------}
function radacina(a: real): real;
begin
   if(a>0) then radacina := exp(ln(a)/2); 
           else radacina := -1;
end; 
{--------------------------------------------------------------}
BEGIN
   e := 0.000001;
   ex := -round(ln(e)/ln(10));
   write('a = '); readln(a);
   writeln('sqrt(a) = ', radacina(a):7:ex);
   readln;
END.