Please follow the following information:
All defenses cost 10 rupees to upgrade ★, 50 rupees to upgrade ★★, 200 rupees to upgrade ★★★, and 500 rupees to upgrade ★★★★. Each ★ increases the same defense value.
The mask of the Ekai team has a defense value of 1 when unenhanced, and a defense value of 13 when upgrade to ★★★★
Please extract the key information and list the process to answer:How many rupees does it cost to upgrade the mask of the Ekai team to ★★? How much will the defense value change to?
 In your entire response, the letter z should appear less than 37.
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