發送短信 : Redundancy allocation for series-parallel warm-standby systems

 _____     _    _                ___     _    _   
|  __ \\  | || | ||     ___     / _ \\  | || | || 
| |  \ || | || | ||    /   ||  | / \ || | || | || 
| |__/ || | \\_/ ||   | [] ||  | \_/ || | \\_/ || 
|_____//   \____//     \__ ||   \___//   \____//  
 -----`     `---`       -|_||   `---`     `---`   
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