#include <iostream>
#include <vector>
#include <unordered_map>
#define int long long
using namespace std;

class PalindromicTree {
private:
    vector<char> st;
    vector<int> length;
    vector<int> parent;
    vector<int> count;
    vector<unordered_map<char, int>> link;
    int lastNodeIdx;

public:
    PalindromicTree() {
        st.push_back(0);
        length.push_back(-1);
        length.push_back(0);
        parent.push_back(0);
        parent.push_back(0);
        count.push_back(0);
        count.push_back(0);
        link.push_back({});
        link.push_back({});
        lastNodeIdx = 0;
    }

    void add(char v) {
        st.push_back(v);
        int prevNodeIdx = lastNodeIdx;
        int nextNodeIdx = lastNodeIdx;
        while (true) {
            int head = length[nextNodeIdx] + 2;
            if (head <= st.size() && st[st.size() - head] == st.back()) {
                break;
            }
            nextNodeIdx = parent[nextNodeIdx];
        }
        int nextLen = length[nextNodeIdx] + 2;
        if (link[nextNodeIdx].count(v)) {
            lastNodeIdx = link[nextNodeIdx][v];
            count[lastNodeIdx]++;
            return;
        }
        lastNodeIdx = length.size();
        length.push_back(nextLen);
        if (nextLen == 1) {
            parent.push_back(1);
        } else {
            int prevNodeIdx = parent[nextNodeIdx];
            while (true) {
                int head = length[prevNodeIdx] + 2;
                if (head <= st.size() && st[st.size() - head] == st.back()) {
                    break;
                }
                prevNodeIdx = parent[prevNodeIdx];
            }
            parent.push_back(link[prevNodeIdx][v]);
        }
        count.push_back(1);
        link[nextNodeIdx][v] = lastNodeIdx;
        link.push_back({});
    }

    int maxScore() {
        int nodeCount = length.size();
        vector<int> score(nodeCount, 0);
        vector<int> tempCount = count;
        for (int i = nodeCount - 1; i >= 2; i--) {
            tempCount[parent[i]] += tempCount[i];
        }
        for (int i = 2; i < nodeCount; i++) {
            score[i] = score[parent[i]] + length[i] * tempCount[i];
        }
        int maxScore = 0;
        for (int s : score) {
            maxScore = max(maxScore, s);
        }
        return maxScore;
    }
};

signed main() {
    string s;
    cin >> s;
    PalindromicTree pt;
    for (int i = s.length() - 1; i >= 0; i--) {
        pt.add(s[i]);
    }
    cout << pt.maxScore() << endl;
    return 0;
}