import sys, os
import numpy as np
import cv2

def interlace(evens, odds):
  '''Reconstruct the image by alternating rows of evens and odds.

  evens - a numpy array of shape (rows, columns, 3)  containing the even rows 
          of the output image.
  odds - a numpy array of shape (rows, columns, 3) containing the odd rows 
         of the output image.

  This function should return an image. Row 0 of the output image should be
  row 0 of evens. Row 1 of the output image should be row 0 of odds. Then
  row 1 of evens, then row 1 of odds, and so on.

  The resulting image will have as many rows as image 1 and 2 combined, equal
  to both in number of columns, and have 3 channels.
  '''
  i=0
  outimg = np.zeros([800,600] , 'uint8')
  # Implement your function here ---------------------------------------------
  while i <= (len(evens) + len(odds)):
    outimg[2*i] = evens[i]
    outimg[2*i + 1] = odds[i]
    i+=1
  #---------------------------------------------------------------------------
  return outimg

i = 0     
outimg = np.zeros((evens.shape[0]*2,evens.shape[1],3),dtype=np.uint8)  
while i <(evens.shape[0]):
    outimg[i*2] = evens[i]
    outimg[i*2+1] = odds[i]
    i+=1