#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
#include <cstdint>
#include <unordered_map>
std::string str;
uint64_t p31[300005] = {1, 31};
uint64_t pfx_hash[300005];
uint64_t pfx_hash_rev[300005];
std::unordered_map<int,int> vis[300005];
std::unordered_map<int,int> freq;
void preprocess() {
for (int i = 2; i < 300005; i++) {
p31[i] = p31[i-1]*31;
}
}
inline uint64_t hquery(uint64_t* pfx_hash, int l, int r) {
uint64_t ret = pfx_hash[r];
if (l-1>=0) {
ret -= pfx_hash[l-1]*p31[r-l+1];
}
return ret;
}
inline bool is_palindrome(int l, int r) {
return hquery(pfx_hash,l,r) == hquery(pfx_hash_rev,str.size()-r-1,str.size()-l-1);
}
void bfs() {
std::queue<std::pair<int,int>> q;
for (int i = 0; i < str.size(); i++) {
vis[i][i] = 1;
freq[hquery(pfx_hash,i,i)] += 1;
q.emplace(i,i);
}
int64_t ret = 0;
while (!q.empty()) {
auto [l, r] = q.front();
q.pop();
//std::cerr << l << " " << r << ", " << freq[hquery(pfx_hash,l,r)] << "\n";
ret = std::max(ret,static_cast<int64_t>(1LL*(r-l+1)*freq[hquery(pfx_hash,l,r)]));
int len = r-l+1;
int le = l+len;
int ri = le+len-1;
if (ri<str.size()&&!vis[l][ri]&&hquery(pfx_hash,l,r)==hquery(pfx_hash_rev,str.size()-ri-1,str.size()-le-1)) {
freq[hquery(pfx_hash,l,ri)] += 1;
vis[l][ri] = 1;
q.emplace(l,ri);
}
le = l+len+1;
ri = le+len-1;
if (ri<str.size()&&!vis[l][ri]&&hquery(pfx_hash,l,r)==hquery(pfx_hash_rev,str.size()-ri-1,str.size()-le-1)) {
freq[hquery(pfx_hash,l,ri)] += 1;
vis[l][ri] = 1;
q.emplace(l,ri);
}
le = l-len;
ri = le+len-1;
if (le>=0&&!vis[le][r]&&hquery(pfx_hash,le,ri)==hquery(pfx_hash_rev,str.size()-r-1,str.size()-l-1)) {
freq[hquery(pfx_hash,le,r)] += 1;
vis[le][r] = 1;
q.emplace(le,r);
}
le = l-len-1;
ri = le+len-1;
if (le>=0&&!vis[le][r]&&hquery(pfx_hash,le,ri)==hquery(pfx_hash_rev,str.size()-r-1,str.size()-l-1)) {
freq[hquery(pfx_hash,le,r)] += 1;
vis[le][r] = 1;
q.emplace(le,r);
}
}
std::cout << ret << "\n";
}
int main() {
preprocess();
std::ios_base::sync_with_stdio(false);
std::cin.tie(NULL);
std::cout.tie(NULL);
std::cin >> str;
for (int i = 0; i < str.size(); i++) {
pfx_hash[i] = ((i-1>=0) ? pfx_hash[i-1]*31 : 0);
pfx_hash[i] += str[i]-'a'+1;
pfx_hash_rev[i] = ((i-1>=0) ? pfx_hash_rev[i-1]*31 : 0);
pfx_hash_rev[i] += str[str.size()-i-1]-'a'+1;
//std::cout << pfx_hash[i] << " " << pfx_hash_rev[i] << "\n";
}
int64_t ret = 0;
for (int len = 1; len <= str.size(); len++) {
std::unordered_map<int,int> map;
for (int l = 0; l+len-1 < str.size(); l++) {
int r = l+len-1;
if (is_palindrome(l,r)) {
++map[hquery(pfx_hash,l,r)];
ret = std::max(ret,static_cast<int64_t>(1LL*len*map[hquery(pfx_hash,l,r)]));
}
}
}
std::cout << ret << "\n";
}
