program lab1_1;

{$APPTYPE CONSOLE}



uses
  System.SysUtils;

var
  first,second,third: double;
  isCorrect: boolean;

begin
  isCorrect:= false ;

  repeat
    try
        writeln('Enter the length of the first segment:');
        readln(first);
        writeln('Enter the length of the second segment:');
        readln(second);
        writeln('Enter the length of the third segment:');
        readln(third);
        isCorrect:=true;
            if ((first<=0) or (second<=0) or (third<=0)) then
                 begin
                 Writeln('The length must be greater than 0!');
                 isCorrect := False;
                 end;


    except
        Writeln('Try again!');
    end;
  until (isCorrect);

  if ( (first+second > third) and (first+third > second) and (second+third > first)) then
    writeln ('Possible.')
  else
    writeln ('Impossible.');
    readln;

end.