Elma is learning chess figures.
She learned that a rook can move either horizontally or vertically. To enhance her understanding of rook movement Elma’s grandmother gave Elma an 8 × 8 chess board and asked her to find a way to move the rook from a1 to h8 making exactly n moves, so that all visited cells are different.
A visited cell is the initial cell a1 and each cell on which the rook lands after a move.
输入描述:
The input contains a single integer n (2 ≤ n ≤ 63) — the desired number of moves.
输出描述:
Output a space-separated list of n+1 visited cells in the order they are visited by the rook. All cells must be different. The list should start with a1 and end with h8. A solution always exists.
备注:
Author: Mikhail Dvorkin