The XYZ Partnership Is Held by Ten Partners Who Have

The XYZ Partnership is held by ten partners who have the following capital and profits ownership of the partnership. The tax year- end used by each of the ten partners is also indicated. Assume each partner has used this year- end for at least five years. $$\begin{array} { | c | c | c | } \hline \text { Partner } & \text { Orvnership } & \text { Partner's Tax Year- End } \\\hline \mathrm{A} & 8 \% & 12 / 31 \\\mathrm{~B} & 8 \% & 6 / 30 \\\mathrm{C} & 8 \% & 9 / 30 \\\mathrm{D} & 10 \% & 6 / 30 \\\mathrm{E} & 10 \% & 6 / 30 \\\mathrm{~F} & 10 \% & 10 / 31 \\\mathrm{G} & 10 \% & 9 / 30 \\\mathrm{H} & 12 \% & 12 / 31 \\\mathrm{I} & 12 \% & 6 / 30 \\\mathrm{~K} & 12 \% & 6 / 30\\\hline\end{array}$$ What is the required year- end for the XYZ Partnership, assuming that the business has no natural business year and has not filed a Sec. 444 election?