program SumEvenDigits;

var
num, digit, sum: integer;

begin
sum := 0;

write('Enter a natural number less than 30000: ');
readln(num);

while (num < 0) or (num >= 30000) do
begin
writeln('Please enter a natural number less than 30000.');
write('Enter a natural number less than 30000: ');
readln(num);
end;

while num > 0 do
begin
digit := num mod 10;
if digit mod 2 = 0 then
sum := sum + digit;
num := num div 10;
end;

writeln('The sum of even digits in the number is: ', sum);

end.