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#include <iostream>
#include <cstring>

class Solution {
public:
    int maximumLength(std::string s) {
        int n = s.length();
        int cnt = 0;
        int cnts[26][3] = { 0 };
        for (int i = 0; i < n; ++i) {
            ++cnt;
            if (i + 1 == n || s[i] != s[i + 1]) {
                int idx = s[i] - 'a';
                for (int j = 0; j < 3; ++j) {
                    if (cnts[idx][j] < cnt) {
                        for (int k = 2; k > j; --k) {
                            cnts[idx][k] = cnts[idx][k - 1];
                        }
                        cnts[idx][j] = cnt--;
                    }
                }
                cnt = 0;
            }
        }
        
        int res = 0;
        for (int i = 0; i < 26; ++i) {
            res = std::max(res, cnts[i][2]);
        }
        return res == 0 ? -1 : res;
    }
};