# Introduction 
Digital Cypher assigns to each letter of the alphabet unique number. For example:
```
 a  b  c  d  e  f  g  h  i  j  k  l  m
 1  2  3  4  5  6  7  8  9 10 11 12 13
 n  o  p  q  r  s  t  u  v  w  x  y  z
14 15 16 17 18 19 20 21 22 23 24 25 26
```
Instead of letters in encrypted word we write the corresponding number, eg. The word scout:
```
 s  c  o  u  t
19  3 15 21 20
```
Then we add to each obtained digit consecutive digits from the key. For example. In case of key equal to `1939` :
```
   s  c  o  u  t
  19  3 15 21 20
 + 1  9  3  9  1
 ---------------
  20 12 18 30 21
   m  a  s  t  e  r  p  i  e  c  e
  13  1 19 20  5 18 16  9  5  3  5
+  1  9  3  9  1  9  3  9  1  9  3
  --------------------------------
  14 10 22 29  6 27 19 18  6  12 8
```
# Task
Write a function that accepts `str` string and `key` number and returns an array of integers representing encoded `str`.
# Input / Output
The `str` input string consists of lowercase characters only.
The `key` input number is a positive integer.
# Example
```
Encode("scout",1939);  ==>  [ 20, 12, 18, 30, 21]
Encode("masterpiece",1939);  ==>  [ 14, 10, 22, 29, 6, 27, 19, 18, 6, 12, 8]
```
# Digital cypher series
- [Digital cypher vol 1](https://www.codewars.com/kata/592e830e043b99888600002d)
- [Digital cypher vol 2](https://www.codewars.com/kata/592edfda5be407b9640000b2)
- [Digital cypher vol 3 - missing key](https://www.codewars.com/kata/5930d8a4b8c2d9e11500002a)
def encode(message, key):
#    alphabet = {
#    'a' : 1, 'b' : 2, 'c' : 3, 'd' : 4, 'e' : 5, 'f' : 6, 'g' : 7, 'h' : 8, 'i' : 9,
#    'j' : 10, 'k' : 11, 'l' : 12, 'm' : 13, 'n' : 14, 'o' : 15, 'p' : 16, 'q' : 17,
#    'r' : 18, 's' : 19, 't' : 20, 'u' : 21, 'v' : 22, 'w' : 23, 'x' : 24, 'y' : 25,
#    'z' : 26
#    }
    key_tracker = 0
    ciphertext = []
    key = [int(k) for k in str(key)]
    letters = [ord(a)-96 for a in message]
    for i in range(len(letters)):
        letters[i] += key[key_tracker]
        key_tracker += 1
        if key_tracker == len(key):
            key_tracker = 0
    return letters
def encode(message, key):
#    alphabet = {
#    'a' : 1, 'b' : 2, 'c' : 3, 'd' : 4, 'e' : 5, 'f' : 6, 'g' : 7, 'h' : 8, 'i' : 9,
#    'j' : 10, 'k' : 11, 'l' : 12, 'm' : 13, 'n' : 14, 'o' : 15, 'p' : 16, 'q' : 17,
#    'r' : 18, 's' : 19, 't' : 20, 'u' : 21, 'v' : 22, 'w' : 23, 'x' : 24, 'y' : 25,
#    'z' : 26
#    }
    key_tracker = 0
    ciphertext = []
    key = [int(k) for k in str(key)]
    letters = [ord(a)-96 for a in message]
    for i in range(len(letters)):
        letters[i] += key[key_tracker]
        key_tracker += 1
        if key_tracker == len(key):
            key_tracker = 0
    return letters