Z

A square array of size 2^N x 2^N is visited in Z-order. In a 2 x 2 array, the cells are visited in this order: upper-left, upper-right, lower-left, lower-right. This order forms a Z shape.

When N > 1, divide the array into four subarrays of size 2^(N-1) x 2^(N-1), then visit those subarrays recursively in the same order: upper-left, upper-right, lower-left, lower-right.

The following figure shows the visit order for an array of size 2^2 x 2^2.

Given N, r, and c, write a program that outputs when the cell at row r and column c is visited.

The following figure shows the visit order when N = 3.

The first line contains three integers N, r, and c.

Print the visit order of the cell at row r and column c.

• 1 <= N <= 15
• 0 <= r, c < 2^N