How to get only keys of changed dictionary items from dictdiffer?

Question

first = {
    "title": "hello",
    "fork_count": 20,
    "stargazers": ["/users/20", "/users/30"],
    "settings": {
        "assignees": [100, 101, 201],
    }
}



second = {
    "title": "hellooo",
    "fork_count": 20,
    "stargazers": ["/users/20", "/users/30", "/users/40"],
    "settings": {
        "assignees": [100, 101, 202],
    }
}

I run

 a = list(diff for diff in list(difer.diff(first, second)))

which returns:

[('change', 'title', ('hello', 'hellooo')), ('add', 'stargazers', [(2, '/users/40')]), ('change', ['settings', 'assignees', 2], (201, 202))]

How do I get only the keys of the dict that were changed? It would be simple with a[1] in for loop but the settings key won't work that way