#include <bits/stdc++.h>
using namespace std;
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) static_cast<int>((x).size())
template<class T, size_t D>
struct vec : vector<vec<T, D - 1>> {
template<class... Args>
vec(size_t n = 0, Args... args)
: vector<vec<T, D - 1>>(n, vec<T, D - 1>(args...)) {}
};
template<class T>
struct vec<T, 1> : vector<T> {
template<class... Args>
vec(Args... args)
: vector<T>(args...) {}
};
template<class T>
inline bool Minimize(T& a, const T& b) { return a > b ? a = b, true : false; }
template<class T>
inline bool Maximize(T& a, const T& b) { return a < b ? a = b, true : false; }
inline int Next(int i, int n) { return i == n - 1 ? 0 : i + 1; }
inline int Prev(int i, int n) { return !i ? n - 1 : i - 1; }
mt19937 rng(static_cast<uint32_t>(chrono::steady_clock::now().time_since_epoch().count()));
vec<pair<int, int>, 1> Manacher(const string& s) {
vec<pair<int, int>, 1> max_palindromes(SZ(s));
for (int i = 0, l = -1, r = -1; i < SZ(s); ++i) {
if (i > r) {
for (l = i - 1, r = i; ~l && r < SZ(s) && s[l] == s[r]; --l, ++r);
max_palindromes[i].first = r - i; ++l; --r;
} else {
if (max_palindromes[l + r - (i - 1)].first < r - i + 1) {
max_palindromes[i].first = max_palindromes[l + r - (i - 1)].first;
} else {
for (++r, l = (i << 1) - 1 - r; ~l && r < SZ(s) && s[l] == s[r]; --l, ++r);
max_palindromes[i].first = r - i; ++l; --r;
}
}
}
for (int i = 0, l = -1, r = -1; i < SZ(s); ++i) {
if (i > r) {
for (l = i - 1, r = i + 1; ~l && r < SZ(s) && s[l] == s[r]; --l, ++r);
max_palindromes[i].second = r - i; ++l; --r;
} else {
if (max_palindromes[l + r - i].second < r - i + 1) {
max_palindromes[i].second = max_palindromes[l + r - i].second;
} else {
for (++r, l = (i << 1) - r; ~l && r < SZ(s) && s[l] == s[r]; --l, ++r);
max_palindromes[i].second = r - i; ++l; --r;
}
}
}
return max_palindromes;
}
struct SuffixArray {
vec<int, 1> ordered_suffixes, ranks, lcps;
SuffixArray(const string& s) {
int n = SZ(s);
ordered_suffixes = vec<int, 1>(n); iota(ALL(ordered_suffixes), 0);
sort(ALL(ordered_suffixes), [&](int i, int j) {
return s[i] < s[j];
});
ranks = vec<int, 1>(n);
for (int i = 1; i < n; ++i) {
ranks[ordered_suffixes[i]] = ranks[ordered_suffixes[i - 1]] + (s[ordered_suffixes[i - 1]] < s[ordered_suffixes[i]]);
}
vec<int, 1> counters(n), next_ordered_suffixes(n), next_ranks(n);
for (int i = 1; ranks[ordered_suffixes.back()] < n - 1; i <<= 1) {
for (int j = 0; j < n; ++j) {
counters[ranks[ordered_suffixes[j]]] = j;
}
for (int j = n - 1; ~j; --j) {
if (ordered_suffixes[j] >= i) {
next_ordered_suffixes[counters[ranks[ordered_suffixes[j] - i]]--] = ordered_suffixes[j] - i;
}
}
for (int j = n - i; j < n; ++j) {
next_ordered_suffixes[counters[ranks[j]]--] = j;
}
ordered_suffixes.swap(next_ordered_suffixes);
next_ranks[ordered_suffixes[0]] = 0;
for (int j = 1; j < n; ++j) {
next_ranks[ordered_suffixes[j]] = next_ranks[ordered_suffixes[j - 1]] + (ranks[ordered_suffixes[j - 1]] != ranks[ordered_suffixes[j]] || ordered_suffixes[j - 1] + i >= n || ranks[ordered_suffixes[j - 1] + i] != ranks[ordered_suffixes[j] + i]);
}
ranks.swap(next_ranks);
}
lcps = vec<int, 1>(n - 1);
for (int i = 0, j = 0; i < n; ++i, j = max(j - 1, 0)) {
if (ranks[i] < n - 1) {
for (int k = ordered_suffixes[ranks[i] + 1]; max(k, i) + j < n && s[k + j] == s[i + j]; ++j);
lcps[ranks[i]] = j;
}
}
}
};
struct DSU {
int n_sets;
vec<int, 1> parents, cardinalities;
DSU(int t_n_sets)
: n_sets(t_n_sets),
parents(n_sets),
cardinalities(n_sets, 1) {
iota(ALL(parents), 0);
}
int Parent(int i) {
return i == parents[i] ? i : parents[i] = Parent(parents[i]);
}
bool SameSet(int i, int j) {
return Parent(i) == Parent(j);
}
bool Unite(int i, int j) {
i = Parent(i); j = Parent(j);
if (i == j) {
return false;
}
if (cardinalities[i] > cardinalities[j]) {
swap(i, j);
}
--n_sets;
parents[i] = j;
cardinalities[j] += cardinalities[i];
return true;
}
};
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
string s; cin >> s;
auto max_palindromes = Manacher(s);
SuffixArray sa(s);
int64_t answer = 0;
for (int i = SZ(s) >> 1; i; --i) {
static vec<int, 1> ordered_positions;
static auto ordered_position = ordered_positions.begin();
if (!SZ(ordered_positions)) {
ordered_positions = vec<int, 1>(SZ(s));
ordered_position = ordered_positions.begin();
iota(ALL(ordered_positions), 0);
sort(ALL(ordered_positions), [&](const auto& x, const auto& y) {
return max_palindromes[sa.ordered_suffixes[x]].first > max_palindromes[sa.ordered_suffixes[y]].first;
});
}
static vec<int, 1> ordered_links;
static auto ordered_link = ordered_links.begin();
if (!SZ(ordered_links)) {
ordered_links = vec<int, 1>(SZ(s) - 1);
ordered_link = ordered_links.begin();
iota(ALL(ordered_links), 0);
sort(ALL(ordered_links), [&](const auto& x, const auto& y) {
return sa.lcps[x] > sa.lcps[y];
});
}
static DSU dsu(SZ(s));
static vec<int, 1> values(SZ(s));
static int max_value = 0;
for (; ordered_link != ordered_links.end() && sa.lcps[*ordered_link] >= i; ++ordered_link) {
int u = dsu.Parent(*ordered_link), v = dsu.Parent((*ordered_link) + 1);
dsu.Unite(u, v);
Maximize(max_value, (values[dsu.Parent(u)] += values[u ^ v ^ dsu.Parent(u)]));
}
for (; ordered_position != ordered_positions.end() && max_palindromes[sa.ordered_suffixes[*ordered_position]].first >= i; ++ordered_position) {
int u = dsu.Parent(*ordered_position);
Maximize(max_value, (++values[u]));
}
Maximize(answer, static_cast<int64_t>(max_value) * (i << 1));
}
for (int i = (SZ(s) + 1) >> 1; i; --i) {
static vec<int, 1> ordered_positions;
static auto ordered_position = ordered_positions.begin();
if (!SZ(ordered_positions)) {
ordered_positions = vec<int, 1>(SZ(s));
ordered_position = ordered_positions.begin();
iota(ALL(ordered_positions), 0);
sort(ALL(ordered_positions), [&](const auto& x, const auto& y) {
return max_palindromes[sa.ordered_suffixes[x]].second > max_palindromes[sa.ordered_suffixes[y]].second;
});
}
static vec<int, 1> ordered_links;
static auto ordered_link = ordered_links.begin();
if (!SZ(ordered_links)) {
ordered_links = vec<int, 1>(SZ(s) - 1);
ordered_link = ordered_links.begin();
iota(ALL(ordered_links), 0);
sort(ALL(ordered_links), [&](const auto& x, const auto& y) {
return sa.lcps[x] > sa.lcps[y];
});
}
static DSU dsu(SZ(s));
static vec<int, 1> values(SZ(s));
static int max_value = 0;
for (; ordered_link != ordered_links.end() && sa.lcps[*ordered_link] >= i; ++ordered_link) {
int u = dsu.Parent(*ordered_link), v = dsu.Parent((*ordered_link) + 1);
dsu.Unite(u, v);
Maximize(max_value, (values[dsu.Parent(u)] += values[u ^ v ^ dsu.Parent(u)]));
}
for (; ordered_position != ordered_positions.end() && max_palindromes[sa.ordered_suffixes[*ordered_position]].second >= i; ++ordered_position) {
int u = dsu.Parent(*ordered_position);
Maximize(max_value, (++values[u]));
}
Maximize(answer, static_cast<int64_t>(max_value) * ((i << 1) - 1));
}
cout << answer << '\n';
return 0;
}
