#include <string.h>
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;

struct palindromic_tree {
    struct Node {
        int link;
        int len;
        int l,r;
        vector<int>to;
        Node(int Link,int Len,int L,int R) {
            link = Link;
            len = Len;
            l = L;
            r = R;
            to.resize(26,-1);
        }
    };
    vector<Node>nodes;
    vector<int>lens;
    vector<int>cnt;
    palindromic_tree(string s) {
        nodes.push_back(Node(-1,-1,0,-1));
        nodes.push_back(Node(0,0,0,0));
        int pre = 0;
        for(int i = 0; i < s.size(); i++) {
            lens.push_back(pre);
            while(pre) {
                int j = i-1-nodes[pre].len;
                if(j >= 0 && s[j] == s[i]) {
                    break;
                }
                pre = nodes[pre].link;
            }
            if(nodes[pre].to[s[i]-'a'] != -1) {
                pre = nodes[pre].to[s[i]-'a'];
                continue;
            }
            int nxt = nodes.size();
            int l = i-1-nodes[pre].len;
            int r = i+1;
            nodes[pre].to[s[i]-'a'] = nxt;
            int link = -1;
            if(pre == 0) {
                link = 1;
            }
            else {
                while(true) {
                    pre = nodes[pre].link;
                    int j = i-1-nodes[pre].len;
                    if(j >= 0 && s[j] == s[i]) {
                        break;
                    }
                }
                link = nodes[pre].to[s[i]-'a'];
            }
            nodes.push_back(Node(link,r-l,l,r));
            pre = nxt;
        }
        lens.push_back(pre);
        cnt.resize(nodes.size());
        for(int i = 0; i < s.size(); i++) {
            cnt[lens[i+1]]++;
        }
        for(int i = nodes.size()-1; i >= 2; i--) {
            cnt[nodes[i].link] += cnt[i];
        }
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    string s;
    cin >> s;
    palindromic_tree tr(s);
    vector<long long>dp(tr.nodes.size());
    for(int i = 2; i < tr.nodes.size(); i++) {
        dp[i] = 1ll*tr.cnt[i]*tr.nodes[i].len;
        dp[i] += dp[tr.nodes[i].link];
    }
    cout << *max_element(dp.begin(),dp.end()) << "\n";
}