#include <bits/stdc++.h>
using namespace std;
using ull = uint64_t;
using u128 = __uint128_t;
using pii = pair<int, int>;
template<class T, class U> bool chmax(T& a, const U& b){ if(a < b){ a = b; return 1; } return 0; }
constexpr ull mod = 0x1fffffffffffffff, base = 257;
struct RollingHash{
const int n;
vector<ull> data, power;
static constexpr ull mul(ull a, ull b){
u128 c = (u128)a * b;
ull ans = ull(c >> 61) + ull(c & mod);
if(ans >= mod) ans -= mod;
return ans;
}
RollingHash(const string& s): n(s.size()), data(n + 1), power(n + 1){
power[0] = 1;
data[0] = 1;
for(int i = 0; i < n; i++){
power[i + 1] = mul(power[i], base);
data[i + 1] = mul(data[i], base) + s[i];
if(data[i + 1] >= mod) data[i + 1] -= mod;
}
}
ull get(int l, int r){
const ull L = mul(data[l], power[r - l]);
const ull R = data[r];
return R - L + (R < L ? mod : 0);
}
};
vector<int> manacher(const string& S){
string s = {S[0]};
for(int i = 1; i < S.size(); i++){
s += '$';
s += S[i];
}
const int n = s.size();
vector a(n, 0);
for(int i = 0, j = 0; i < n; ){
while(i - j >= 0 && i + j < n && s[i - j] == s[i + j]) j++;
a[i] = j;
int k = 1;
for(; i - k >= 0 && i + k < n && k + a[i - k] < j; k++) a[i + k] = a[i - k];
i += k;
j -= k;
}
return a;
}
int main(){
string s;
cin >> s;
RollingHash rh(s);
auto a = manacher(s);
auto comp = [](pii a, pii b){ return a.second - a.first < b.second - b.first; };
priority_queue<pii, vector<pii>, decltype(comp)> q(comp);
unordered_map<ull, ull> cnt;
for(int i = 0; i < a.size(); i++){
int l = (i - a[i] + 2) / 2, r = (i + a[i] + 1) / 2;
if(l >= r) continue;
auto [iter, changed] = cnt.try_emplace(rh.get(l, r), 0);
if(changed) q.emplace(l, r);
iter->second++;
}
ull ans = 0;
while(q.size()){
auto [l, r] = q.top();
q.pop();
ull a = cnt[rh.get(l, r)];
chmax(ans, a * (r - l));
l++; r--;
if(l < r){
auto [iter, changed] = cnt.try_emplace(rh.get(l, r), 0);
if(changed) q.emplace(l, r);
iter->second += a;
}
}
cout << ans << endl;
}
