ZeroDivisionError: integer division or modulo by zero error question

I'm solving Josephus problem on Baekjun site (https://www.acmicpc.net/problem/1158), the code below is correct algorithm except for output format.

N, k = map(int, input().split())

A = [x for x in range (1,N+1)]
answer = []
idx = 0

for i in range(N):
    idx = (idx + k - 1) % len(A)
    answer.append(A[idx])
    del A[idx]

print(answer)

However, if I change the repetition statement fori in range(N): to whilelen(answer) <=N:, I get a ZeroDivisionError: integrer division or modulo by zero error. I think it's an error that doesn't have anything to do with the form of the repeat statement, but does anyone know why this error occurs?