var
y,x:real;
begin
write ('X = ');readln(x);
if x<0 then writeln ('Y does not exist') else begin
y:=sqrt(x);
writeln ('Y = ',y:0:4);
end;
readln;
end.
var
y,x:real;
begin
write ('X = ');readln(x);
if x<0 then writeln ('Y does not exist') else begin
y:=sqrt(x);
writeln ('Y = ',y:0:4);
end;
readln;
end.