class Solution {
public:
    int compress(vector<char>& chars) {
        int ans = 0;
        int count = 0;

        chars.insert(chars.begin(), chars.begin(), chars.begin()+1);

        vector<char> &s = chars;
        /*
        cout << "[";
        for (auto ch : s) {
            cout << ch << ", ";
        }
        cout << "]" << endl;
        */

        int j = 1;
        for (int i = 1; i < s.size(); i++) {
            if (s[i] == s[i-1])
                count++;
            else {
                // cout << s[i-1] << " : ";

                s[j++] = s[i-1];
                if (count > 1) {
                    string tmp = to_string(count);
                    ans += 1 + tmp.size();

                    for (const auto &ch : tmp) {
                        s[j++] = ch;
                    }
                }
                else {
                    ans++;
                }
                
                // cout << count << endl;

                count = 1;
            }
        }

        // cout << s.back() << " : " << count << endl;

        s[j++] = s.back();
        if (count > 1) {
            string tmp = to_string(count);
            ans += 1 + tmp.size();

            for(const auto &ch : tmp)
                chars[j++] = ch;
        }
        else {
            ans ++;
        }

        chars.erase(chars.begin());

        return ans;
    }
};