#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define per(i, n) for (int i = (n)-1; i >= 0; i--)
#define rep2(i, l, r) for (int i = (l); i < (r); i++)
#define per2(i, l, r) for (int i = (r)-1; i >= (l); i--)
#define each(e, v) for (auto &e : v)
#define MM << " " <<
#define pb push_back
#define eb emplace_back
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sz(x) (int)x.size()
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;

template <typename T>
using minheap = priority_queue<T, vector<T>, greater<T>>;

template <typename T>
using maxheap = priority_queue<T>;

template <typename T>
bool chmax(T &x, const T &y) {
    return (x < y) ? (x = y, true) : false;
}

template <typename T>
bool chmin(T &x, const T &y) {
    return (x > y) ? (x = y, true) : false;
}

template <typename T>
int flg(T x, int i) {
    return (x >> i) & 1;
}

int pct(int x) { return __builtin_popcount(x); }
int pct(ll x) { return __builtin_popcountll(x); }
int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
int botbit(int x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int botbit(ll x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }

template <typename T>
void print(const vector<T> &v, T x = 0) {
    int n = v.size();
    for (int i = 0; i < n; i++) cout << v[i] + x << (i == n - 1 ? '\n' : ' ');
    if (v.empty()) cout << '\n';
}

template <typename T>
void printn(const vector<T> &v, T x = 0) {
    int n = v.size();
    for (int i = 0; i < n; i++) cout << v[i] + x << '\n';
}

template <typename T>
int lb(const vector<T> &v, T x) {
    return lower_bound(begin(v), end(v), x) - begin(v);
}

template <typename T>
int ub(const vector<T> &v, T x) {
    return upper_bound(begin(v), end(v), x) - begin(v);
}

template <typename T>
void rearrange(vector<T> &v) {
    sort(begin(v), end(v));
    v.erase(unique(begin(v), end(v)), end(v));
}

template <typename T>
vector<int> id_sort(const vector<T> &v, bool greater = false) {
    int n = v.size();
    vector<int> ret(n);
    iota(begin(ret), end(ret), 0);
    sort(begin(ret), end(ret), [&](int i, int j) { return greater ? v[i] > v[j] : v[i] < v[j]; });
    return ret;
}

template <typename T>
void reorder(vector<T> &a, const vector<int> &ord) {
    int n = a.size();
    vector<T> b(n);
    for (int i = 0; i < n; i++) b[i] = a[ord[i]];
    swap(a, b);
}

template <typename T>
T floor(T x, T y) {
    assert(y != 0);
    if (y < 0) x = -x, y = -y;
    return (x >= 0 ? x / y : (x - y + 1) / y);
}

template <typename T>
T ceil(T x, T y) {
    assert(y != 0);
    if (y < 0) x = -x, y = -y;
    return (x >= 0 ? (x + y - 1) / y : x / y);
}

template <typename S, typename T>
pair<S, T> operator+(const pair<S, T> &p, const pair<S, T> &q) {
    return make_pair(p.first + q.first, p.second + q.second);
}

template <typename S, typename T>
pair<S, T> operator-(const pair<S, T> &p, const pair<S, T> &q) {
    return make_pair(p.first - q.first, p.second - q.second);
}

template <typename S, typename T>
istream &operator>>(istream &is, pair<S, T> &p) {
    S a;
    T b;
    is >> a >> b;
    p = make_pair(a, b);
    return is;
}

template <typename S, typename T>
ostream &operator<<(ostream &os, const pair<S, T> &p) {
    return os << p.first << ' ' << p.second;
}

struct io_setup {
    io_setup() {
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout << fixed << setprecision(15);
        cerr << fixed << setprecision(15);
    }
} io_setup;

constexpr int inf = (1 << 30) - 1;
constexpr ll INF = (1LL << 60) - 1;
// constexpr int MOD = 1000000007;
constexpr int MOD = 998244353;

template <int char_size, char base>
struct Palindrome_Tree {
    struct Node {
        array<int, char_size> next;
        int len, count, suffix_link;

        Node(int len, int suffix_link) : len(len), count(0), suffix_link(suffix_link) { fill(begin(next), end(next), -1); }
    };

    vector<Node> nodes;
    string s;
    int n;
    vector<int> longest_palindromes; // i 文字目を末尾とする最長回文の index を格納

    Palindrome_Tree() : n(0) {
        nodes.emplace_back(-1, -1); // 奇数長の空回文
        nodes.emplace_back(0, 0);   // 偶数長の空回文
    }

    Palindrome_Tree(string s) : Palindrome_Tree() {
        for (char c : s) push_back(c);
        build_frequency();
    }

    // 回文の種類数
    int count() { return (int)nodes.size() - 2; }

    // r-1 文字目を末尾とする palindrome に c を追加したときの suffix_link
    int suffix_palindrome(int palindrome, char c, int r) {
        while (palindrome != -1) {
            const Node &node = nodes[palindrome];
            if (node.len < r && s[r - 1 - node.len] == c) return palindrome;
            palindrome = node.suffix_link;
        }
        return -1;
    }

    void push_back(char c) {
        s.push_back(c);
        n++;
        int current_palindrome = (n == 1 ? 0 : longest_palindromes.back());
        int p = suffix_palindrome(current_palindrome, c, n - 1);
        if (nodes[p].next[c - base] == -1) {
            nodes[p].next[c - base] = (int)nodes.size();
            int q = suffix_palindrome(nodes[p].suffix_link, c, n - 1);
            if (q != -1) {
                nodes.emplace_back(nodes[p].len + 2, nodes[q].next[c - base]);
            } else {
                nodes.emplace_back(1, 1);
            }
        }
        int palindrome = nodes[p].next[c - base];
        nodes[palindrome].count++;
        longest_palindromes.push_back(palindrome);
    }

    void build_frequency() {
        for (int i = (int)nodes.size() - 1; i > 0; i--) {
            int suffix = nodes[i].suffix_link;
            nodes[suffix].count += nodes[i].count;
        }
    }

    void solve() {
        int L = sz(nodes);
        vector<ll> dp(L, 0);
        rep(i, L) {
            auto e = nodes[i];
            // cout << i MM e.len MM e.count << endl;
            if (e.len > 0) dp[i] += 1LL * e.len * e.count;
            if (e.suffix_link >= 0) dp[i] += dp[e.suffix_link];
        }
        ll ans = 0;
        rep(i, L) chmax(ans, dp[i]);
        cout << ans << '\n';
    }
};

void solve() {
    string S;
    cin >> S;

    Palindrome_Tree<26, 'a'> P(S);
    // P.build_frequency();
    P.solve();
}

int main() {
    int T = 1;
    // cin >> T;
    while (T--) solve();
}