string appendAndDelete(string s, string t, int k) {
    int same_letters = 0;
    int cnt1 = s.size();
    int cnt2 = t.size();
    int min_val = min(cnt1, cnt2);

    for (int i = 0; i < min_val; i++) {
        if (s[i] == t[i]) {
            same_letters++;
        } else break;
    }

    int amount = (cnt1 - same_letters) + (cnt2 - same_letters);

    if (amount == k) {
        return "Yes" ;
    } else if (amount < k) {
        if ((k - amount) % 2 == 0 || k >= cnt1 + cnt2) {
            return "Yes";
        }
    }

    return "No";
}