How to return the smaller of an OR operator regex when both are present?

Question

This regex:

    import re
    string = 'I am a long string with many regexes matching'
    pattern = '.*(?:with|regexes)'
    print(re.findall(pattern, string))

returns

['I am a long string with many regexes']

How can I instead make it return:

['I am a long string with']

i.e. when both the short and long version of the regex is present, return the shorter string.