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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.