String Zig-Zag Pattern-Python

Given a string S and an integer N as the input, the program must split the string into groups whose size is N and print them as the output in separate lines in a zig zag manner. If the last group size is less than N then the remaining letters must be filled with asterisk as shown in the Example Input/Output.

Input Format:

The first line contains S.
The second line contains N.

Output Format:
LENGTH(S)/N + LENGTH(S)%N lines containing the desired pattern.

Boundary Conditions:
4 <= LENGTH(S) <= 500
2 <= N <= LENGTH(S)

Example Input/Output 1:
Input:
ENVIRONMENT
3

Output:
ENV
ORI
NME
*TN

Example Input/Output 2:
Input:
ENVIRONMENT
4

Output:
ENVI
MNOR
ENT*

Example Input/Output 3:
Input:
EVERYDAY
2

Output:
EV
RE
YD
YA

 Source Code:

n,m,l=list(input().strip()),int(input()),0

c=m

while len(n)%m!=0:

    n.append('*')

d=len(n)

for i in range(d):

    if i%2==0:

        print(''.join(n[l:m]))

    else:

        print(''.join(n[l:m][::-1]))

    l+=c

    m+=c