auto geometricMean(T)(T args)
{
    return pow(args[0], 1.0 / args[1]);
}

void main()
{
    auto numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
    auto average = numbers
        .filter!(n => n > 0 && n % 2 == 1)
        .adjoin!(s => s.fold!((a, b) => a * b)(1), count).geometricMean;
    writeln(average);
}