Text this: A uniformly most powerful cumulative sum scheme based on symmetry

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 /_____//  \ \\/ //  / ____||   / _ \\  | || | || 
 `____ `    \ ` //  / //---`'  | / \ || | || | || 
 /___//      | ||   \ \\___    | \_/ || | \\_/ || 
 `__ `       |_||    \_____||   \___//   \____//  
 /_//        `-`'     `----`    `---`     `---`   
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