Shuffling

Chef simulating the next process, imagine that we have an array A = {1, 2, ..., M}. Split it into two arrays with equal size with odd and even indexes from it. After that let's erase in each array numbers on the place [S*X/Y], where S denoting the size of array and merge these arrays(the first element of the second array will be after the last element of the first array), after the first operation