Codality demo fails on last case

Trying to do the codality demo: return lowest positive integer not in array,

But I can't get my code to pass the last test and I can't see what the test is. I personally can't get my code to fail, so I must be missing something, here is my python3 code:

# you can write to stdout for debugging purposes, e.g.
# print("this is a debug message")

def solution(A):
    # write your code in Python 3.6
    S = set(A)
    i = 1
    for n in S:
        if n < 1:
            continue
        elif i != n:
            break
        else:
            i += 1
    return i 

The test that fails is: large_3 chaotic + many -1, 1, 2, 3 (with minus) ✘WRONG ANSWER got 1 expected 10000

I am using set to put the list in order as well as remove multiple possible values. I understand that set puts negative integers in descending order after positive integers.

What is in this test case that is causing my code to fail?