#line 1 "library/Template/template.hpp"
#include <bits/stdc++.h>
using namespace std;

#define rep(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define ALL(v) (v).begin(),(v).end()
#define UNIQUE(v) sort(ALL(v)),(v).erase(unique(ALL(v)),(v).end())
#define SZ(v) (int)v.size()
#define MIN(v) *min_element(ALL(v))
#define MAX(v) *max_element(ALL(v))
#define LB(v,x) int(lower_bound(ALL(v),(x))-(v).begin())
#define UB(v,x) int(upper_bound(ALL(v),(x))-(v).begin())

using ll=long long int;
using ull=unsigned long long;
using i128=__int128_t;
using u128=__uint128_t;
const int inf = 0x3fffffff;
const ll INF = 0x1fffffffffffffff;

template<typename T>inline bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
template<typename T>inline bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<typename T,typename U>T ceil(T x,U y){assert(y!=0); if(y<0)x=-x,y=-y; return (x>0?(x+y-1)/y:x/y);}
template<typename T,typename U>T floor(T x,U y){assert(y!=0); if(y<0)x=-x,y=-y; return (x>0?x/y:(x-y+1)/y);}
template<typename T>int popcnt(T x){return __builtin_popcountll(x);}
template<typename T>int topbit(T x){return (x==0?-1:63-__builtin_clzll(x));}
template<typename T>int lowbit(T x){return (x==0?-1:__builtin_ctzll(x));}
#line 2 "library/Utility/fastio.hpp"
#include <unistd.h>

class FastIO {
    static constexpr int L = 1 << 16;
    char rdbuf[L];
    int rdLeft = 0, rdRight = 0;
    inline void reload() {
        int len = rdRight - rdLeft;
        memmove(rdbuf, rdbuf + rdLeft, len);
        rdLeft = 0, rdRight = len;
        rdRight += fread(rdbuf + len, 1, L - len, stdin);
    }
    inline bool skip() {
        for (;;) {
            while (rdLeft != rdRight and rdbuf[rdLeft] <= ' ')
                rdLeft++;
            if (rdLeft == rdRight) {
                reload();
                if (rdLeft == rdRight)
                    return false;
            } else
                break;
        }
        return true;
    }
    template <typename T, enable_if_t<is_integral<T>::value, int> = 0>
    inline bool _read(T &x) {
        if (!skip())
            return false;
        if (rdLeft + 20 >= rdRight)
            reload();
        bool neg = false;
        if (rdbuf[rdLeft] == '-') {
            neg = true;
            rdLeft++;
        }
        x = 0;
        while (rdbuf[rdLeft] >= '0' and rdLeft < rdRight) {
            x = x * 10 +
                (neg ? -(rdbuf[rdLeft++] ^ 48) : (rdbuf[rdLeft++] ^ 48));
        }
        return true;
    }
    inline bool _read(__int128_t &x) {
        if (!skip())
            return false;
        if (rdLeft + 40 >= rdRight)
            reload();
        bool neg = false;
        if (rdbuf[rdLeft] == '-') {
            neg = true;
            rdLeft++;
        }
        x = 0;
        while (rdbuf[rdLeft] >= '0' and rdLeft < rdRight) {
            x = x * 10 +
                (neg ? -(rdbuf[rdLeft++] ^ 48) : (rdbuf[rdLeft++] ^ 48));
        }
        return true;
    }
    inline bool _read(__uint128_t &x) {
        if (!skip())
            return false;
        if (rdLeft + 40 >= rdRight)
            reload();
        x = 0;
        while (rdbuf[rdLeft] >= '0' and rdLeft < rdRight) {
            x = x * 10 + (rdbuf[rdLeft++] ^ 48);
        }
        return true;
    }
    template <typename T, enable_if_t<is_floating_point<T>::value, int> = 0>
    inline bool _read(T &x) {
        if (!skip())
            return false;
        if (rdLeft + 20 >= rdRight)
            reload();
        bool neg = false;
        if (rdbuf[rdLeft] == '-') {
            neg = true;
            rdLeft++;
        }
        x = 0;
        while (rdbuf[rdLeft] >= '0' and rdbuf[rdLeft] <= '9' and
               rdLeft < rdRight) {
            x = x * 10 + (rdbuf[rdLeft++] ^ 48);
        }
        if (rdbuf[rdLeft] != '.')
            return true;
        rdLeft++;
        T base = .1;
        while (rdbuf[rdLeft] >= '0' and rdbuf[rdLeft] <= '9' and
               rdLeft < rdRight) {
            x += base * (rdbuf[rdLeft++] ^ 48);
            base *= .1;
        }
        if (neg)
            x = -x;
        return true;
    }
    inline bool _read(char &x) {
        if (!skip())
            return false;
        if (rdLeft + 1 >= rdRight)
            reload();
        x = rdbuf[rdLeft++];
        return true;
    }
    inline bool _read(string &x) {
        if (!skip())
            return false;
        for (;;) {
            int pos = rdLeft;
            while (pos < rdRight and rdbuf[pos] > ' ')
                pos++;
            x.append(rdbuf + rdLeft, pos - rdLeft);
            if (rdLeft == pos)
                break;
            rdLeft = pos;
            if (rdLeft == rdRight)
                reload();
            else
                break;
        }
        return true;
    }
    template <typename T> inline bool _read(vector<T> &v) {
        for (auto &x : v) {
            if (!_read(x))
                return false;
        }
        return true;
    }

    char wtbuf[L], tmp[50];
    int wtRight = 0;
    inline void _write(const char &x) {
        if (wtRight > L - 32)
            flush();
        wtbuf[wtRight++] = x;
    }
    inline void _write(const string &x) {
        for (auto &c : x)
            _write(c);
    }
    template <typename T, enable_if_t<is_integral<T>::value, int> = 0>
    inline void _write(T x) {
        if (wtRight > L - 32)
            flush();
        if (x == 0) {
            _write('0');
            return;
        } else if (x < 0) {
            _write('-');
            if (__builtin_expect(x == std::numeric_limits<T>::min(), 0)) {
                switch (sizeof(x)) {
                case 2:
                    _write("32768");
                    return;
                case 4:
                    _write("2147483648");
                    return;
                case 8:
                    _write("9223372036854775808");
                    return;
                }
            }
            x = -x;
        }
        int pos = 0;
        while (x != 0) {
            tmp[pos++] = char((x % 10) | 48);
            x /= 10;
        }
        rep(i, 0, pos) wtbuf[wtRight + i] = tmp[pos - 1 - i];
        wtRight += pos;
    }
    inline void _write(__int128_t x) {
        if (wtRight > L - 40)
            flush();
        if (x == 0) {
            _write('0');
            return;
        } else if (x < 0) {
            _write('-');
            x = -x;
        }
        int pos = 0;
        while (x != 0) {
            tmp[pos++] = char((x % 10) | 48);
            x /= 10;
        }
        rep(i, 0, pos) wtbuf[wtRight + i] = tmp[pos - 1 - i];
        wtRight += pos;
    }
    inline void _write(__uint128_t x) {
        if (wtRight > L - 40)
            flush();
        if (x == 0) {
            _write('0');
            return;
        }
        int pos = 0;
        while (x != 0) {
            tmp[pos++] = char((x % 10) | 48);
            x /= 10;
        }
        rep(i, 0, pos) wtbuf[wtRight + i] = tmp[pos - 1 - i];
        wtRight += pos;
    }
    inline void _write(double x) {
        ostringstream oss;
        oss << fixed << setprecision(15) << double(x);
        string s = oss.str();
        _write(s);
    }
    template <typename T> inline void _write(const vector<T> &v) {
        rep(i, 0, v.size()) {
            if (i)
                _write(' ');
            _write(v[i]);
        }
    }

  public:
    FastIO() {}
    ~FastIO() { flush(); }
    inline void read() {}
    template <typename Head, typename... Tail>
    inline void read(Head &head, Tail &...tail) {
        assert(_read(head));
        read(tail...);
    }
    template <bool ln = true, bool space = false> inline void write() {
        if (ln)
            _write('\n');
    }
    template <bool ln = true, bool space = false, typename Head,
              typename... Tail>
    inline void write(const Head &head, const Tail &...tail) {
        if (space)
            _write(' ');
        _write(head);
        write<ln, true>(tail...);
    }
    inline void flush() {
        fwrite(wtbuf, 1, wtRight, stdout);
        wtRight = 0;
    }
};

/**
 * @brief Fast IO
 */
#line 3 "sol.cpp"

#line 2 "library/String/palindromictree.hpp"

struct PalindromicTree {
    struct Node {
        map<char, int> nxt;
        int link, len, id, cnt;
        Node() {}
        Node(int link, int len, int id, int cnt)
            : link(link), len(len), id(id), cnt(cnt) {}
    };
    vector<Node> nodes;
    PalindromicTree() {}
    template <typename T> PalindromicTree(const T &S) {
        nodes.push_back(Node(0, -1, -1, 0));
        nodes.push_back(Node(0, 0, -1, 0));
        int cur = 0;

        rep(i, 0, SZ(S)) {
            int k = find(i, cur, S);
            char c = S[i];
            if (nodes[k].nxt.count(c)) {
                cur = nodes[k].nxt[c];
                nodes[cur].cnt++;
                continue;
            }
            nodes[k].nxt[c] = SZ(nodes);
            cur = SZ(nodes);
            nodes.push_back(
                Node(-1, nodes[k].len + 2, i - nodes[k].len - 1, 1));
            if (nodes.back().len == 1)
                nodes.back().link = 1;
            else {
                int n = find(i, nodes[k].link, S);
                nodes.back().link = nodes[n].nxt[c];
            }
        }
    }
    vector<array<int, 3>> get_freq() {
        vector<array<int, 3>> ret;
        for (int i = SZ(nodes) - 1; i >= 2; i--) {
            ret.push_back({nodes[i].len, nodes[i].id, nodes[i].cnt});
            nodes[nodes[i].link].cnt += nodes[i].cnt;
        }
        return ret;
    }

  private:
    template <typename T> int find(int last, int k, const T &S) const {
        for (;;) {
            int i = last - 1 - nodes[k].len;
            if (i >= 0 and S[i] == S[last])
                break;
            k = nodes[k].link;
        }
        return k;
    }
};

/**
 * @brief Palindromic Tree
 */
#line 5 "sol.cpp"

FastIO io;
int main() {
    string s;
    io.read(s);

    PalindromicTree tree(s);
    tree.get_freq();
    vector<ll> dp(tree.nodes.size());
    rep(i, 0, SZ(tree.nodes)) {
        dp[i] = dp[tree.nodes[i].link] + tree.nodes[i].cnt * tree.nodes[i].len;
    }
    ll ret = *max_element(ALL(dp));
    io.write(ret);
    return 0;
}