You are given an m x n integer matrix heights representing the height of each unit cell in a continent. The Pacific ocean touches the continent's left and top edges, and the Atlantic ocean touches the continent's right and bottom edges.
Water can only flow in four directions: up, down, left, and right. Water flows from a cell to an adjacent one with an equal or lower height.
Print all the grid coordinates where water can flow to both the Pacific and Atlantic oceans.
Constraints:
m == heights.length
n == heights[i].length
1 <= m, n <= 200
1 <= heights[i][j] <= 105
Input
Input is given from Standard Input in the following format.
m n
X00 X01 ....... X0n
.
.
Xm0 Xm1 .........Xmn
Output
Print all the coordinates(space separated) in new line.