Input: 	[[0,0,0,5],[4,3,1,4],[0,1,1,4],[1,2,1,3],[0,0,1,1]]
Output: 	[[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,0]]
Expected: 	[[0,0,0,0],[0,0,0,4],[0,0,0,0],[0,0,0,3],[0,0,0,0]]