Edit the following Python code to calculate the sum of all the elements in a two-dimensional array.
arr = [[1,2,3], [4,5,6], [7,8,9]]
arr = [[1,2,3], [4,5,6], [7,8,9]]

sum = 0

for row in arr:
 for col in row:
  sum = sum + col

print("Sum:", sum)