program Multiple13;

var
	base10	:Integer;

function ToBaseN(base,number:Integer):Integer;
begin
	if number = 0 then
		ToBaseN := 0
	else
		ToBaseN := ToBaseN(base,number div 10) * base + number mod 10
end;

begin
	base10 := 10;
	while ToBaseN(13,base10) mod base10 <> 0 do
		base10 := base10 + 1;
	WriteLn(base10)
end.