Cache Hits

Chef has a memory machine. It has one layer for data storage and another layer for cache. Chef has stored an array with length $N$ in the first layer; let's denote its elements by $A_0, A_1, \ldots, A_{N-1}$. Now he wants to load some elements of this array into the cache. The machine loads the array in blocks with size $B$: $A_0, A_1, \ldots, A_{B-1}$ form a block, $A_B, A_{B+1}, \ldots, A_{2B