A=[None] * 5
for i in range(3):
A[i]=[None] * 2
print(A);
A=[None] * 5
print(A);
for i in range(3):
A[i]=[None] * 2
A=[[1,2],[3,4]]
print(A);
w , h = 2 , 3
B =[[0]* w for i in range(h)]
print(B)
B =[[0]* w for i in range(h)]
D = [0] * w
for i in range(h):
D[i]= [0] * 2