You are going to act as a Python interpreter. You will be given a valid python program below. Write down what you think the result of its execution would be. Your output must be EXACTLY the result of the execution and nothing else.
situation
system
def shortestBeautifulSubstring(s: str, k: int) -> str:
    N = len(s)
    min_len = inf
    ans = 'z' * 101

    for right in range(N + 1):
        for left in range(right):
            ss = s[left:right]
            if ss.count('1') == k:
                if len(ss) < min_len or (len(ss) == min_len and ss < ans):
                    min_len = len(ss)
                    ans = ss

    return "" if min_len == inf else ans
user
'11'
assistant