An array of size N x M represents pixels of an image.
Each cell of this array contains an array of size 3 with the pixel's color information: `[R,G,B]`

Convert the color image, into an *average* greyscale image. 

The `[R,G,B]` array contains integers between 0 and 255 for each color. 

To transform a color pixel into a greyscale pixel, average the values of that pixel:
```
p = [R,G,B] => [(R+G+B)/3, (R+G+B)/3, (R+G+B)/3]
```

**Note:** the values for the pixel must be integers, therefore you should round floats to the nearest integer.

## Example

Here's an example of a 2x2 image: 
 
Here's the expected image after transformation:


You are always welcome to check out some of my other katas:

Very Easy (Kyu 8)
Add Numbers
Easy (Kyu 7-6)
Convert Color image to greyscale
Array Transformations
Basic Compression
Find Primes in Range
No Ifs No Buts
Medium (Kyu 5-4)
Identify Frames In An Image
Photoshop Like - Magic Wand
Scientific Notation
Vending Machine - FSA
Find Matching Parenthesis
Hard (Kyu 3-2)
Ascii Art Generator

Difficulty: introductory

Starter code:

def color_2_grey(colors):
	

Solutions:
from statistics import mean

def grey(rgb):
    return [int(round(mean(rgb)))]*3

def color_2_grey(colors):
    return [[grey(pixel) for pixel in row] for row in colors]

def color_2_grey(colors):
    return [ [ [int(round(sum(rgb) / 3))] * 3 for rgb in row ] for row in colors ]

def color_2_grey(colors):
    for line in colors:
        for pixel in line:
            grey = int((sum(pixel)/3)+0.5)
            pixel[0] = grey
            pixel[1] = grey
            pixel[2] = grey
    return colors

def color_2_grey(a):
    return [[[round(sum(y) / 3)] * 3 for y in x] for x in a]

def color_2_grey(colors):
    return [[[round(sum(p)/3) for i in p] for p in r] for r in colors]

def color_2_grey(colors):
    
    res = []
    for row in colors:
        g_row = []
        for pix in row:
            g_pix = []
            for c in pix:
                g_pix.append(int(round(sum(pix)/3, 0)))
            g_row.append(g_pix)
        res.append(g_row)
    return res

def color_2_grey(colors):
    return [[ [round(sum(pixel)/3)]*3 for pixel in line ] for line in colors ]

def color_2_grey(colors):
    return [[[round((r + g + b) / 3)] * 3 for r, g, b in row] for row in colors]

def color_2_grey(colors):
    for i in range(len(colors)):
        for j in range(len(colors[i])):
            t = (colors[i][j][0]+colors[i][j][1]+colors[i][j][2])/3
            colors[i][j].remove(colors[i][j][0])
            colors[i][j].remove(colors[i][j][0])
            colors[i][j].remove(colors[i][j][0]) 
            colors[i][j].append((t+0.5)//1)
            colors[i][j].append((t+0.5)//1)
            colors[i][j].append((t+0.5)//1)
    return colors

def color_2_grey(colors):
    return [[[round((R+G+B)/3)]*3 for [R,G,B] in row] for row in colors]