很奇怪,有两个用例通过不了,有没大神解答一下为啥?

问题:两个用力同样都是出现重复元素,但是有些通过的了有些通过不了

import itertools 
s = ['+','-','*','/']  
s_lists = list(itertools.combinations_with_replacement(s, 3))  
n = list(map(str, input().split()))  
n_lists = list(itertools.combinations_with_replacement(n, 4))  
res = []  
for i in range(len(n_lists)):  
    q,w,e,f = n_lists[i]  
    for j in range(len(s_lists)):  
        a,b,c = s_lists[j]  
        result = eval(f'{q}{a}{w}{b}{e}{c}{f}')  
        res.append(result)  
if 24 in res:  
    print('true')  
else:  
    print('false')