BOJ - 2061 - 좋은 암호

import sys

def solution():
    P, K = map(int, sys.stdin.readline().split(' '))
    
    CHECK = [False, False] + [True] * K 
    for i in range(2, K):
        if CHECK[i]:
            for j in range(2 * i, K+1, i):
                CHECK[j] = False
    primes = [i for i in range(2, K+1) if CHECK[i]]

    cnt = 0
    for i in primes:
        if P % i == 0:
            if i < K:
                print("BAD", i)
                break
            else:
                print("GOOD")
                break
        else:
            cnt += 1
            if cnt == len(primes):
                print("GOOD")

solution()

https://www.acmicpc.net/problem/2061