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A multi-level flash memory is designed to have 16 levels, say from 0 through 15, to store data. This means that each level represents a four bit data. The error nature of this memory can be modeled as follows: A stored digit at level i can stay at this level with probability (1 p), may change to (i 1) (mod 16) with probability p/2, or may change to (i + 1) (mod 16) with probabilty p/2. Find the capacity of this memory channel