#include <bits/stdc++.h>
using namespace std;
void print() {cout<<endl;}
template<typename T,typename... E>
void print(T t,E... e) {cout<<t<<(sizeof...(e)?" ":"");print(e...);}
#define forn(i,x,n) for(int i=int(x);i<int(n);++i)
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define F first
#define S second
#define endl "\n"
typedef long long ll;
typedef pair<int, int> pii;
inline int add(int a, int b, const int &mod) { return a+b >= mod ? a+b-mod : a+b; }
inline int sbt(int a, int b, const int &mod) { return a-b < 0 ? a-b+mod : a-b; }
inline int mul(int a, int b, const int &mod) { return 1ll*a*b % mod; }
const int X[] = {257, 359};
const int MOD[] = {(int)1e9+7, (int)1e9+9};
vector<int> xpow[2];
struct hashing {
vector<int> h[2];
hashing(string &s) {
int n = s.size();
for (int j = 0; j < 2; ++j) {
h[j].resize(n+1);
for (int i = 1; i <= n; ++i) {
h[j][i] = add(mul(h[j][i-1], X[j], MOD[j]), s[i-1], MOD[j]);
}
}
}
// Hash del substring en el rango [i, j)
ll value(int l, int r) {
int a = sbt(h[0][r], mul(h[0][l], xpow[0][r-l], MOD[0]), MOD[0]);
int b = sbt(h[1][r], mul(h[1][l], xpow[1][r-l], MOD[1]), MOD[1]);
return (ll(a)<<32) + b;
}
};
void calc_xpow(int mxlen) {
for (int j = 0; j < 2; ++j) {
xpow[j].resize(mxlen+1, 1);
for (int i = 1; i <= mxlen; ++i) {
xpow[j][i] = mul(xpow[j][i-1], X[j], MOD[j]);
}
}
}
string parse(string &s) {
string t = "%";
for (auto &c : s) t.pb('#'), t.pb(c);
t += "#$";
return t;
}
vector<int> manacher(string &s) {
string t = parse(s);
int n = t.size();
vector<int> p(n, 0);
int c = 0, r = 0;
for (int i = 1; i < n-1; i++) {
int j = c - (i-c) ;
if (r > i) p[i] = min(r-i, p[j]);
while (t[i+1+p[i]] == t[i-1-p[i]])
p[i]++;
if (i+p[i] > r) {
c = i;
r = i+p[i];
}
}
return p;
}
const int N = 3e5+5;
set<ll> palin[N];
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
string s;
cin >> s;
int n = s.size();
auto p = manacher(s);
int m = p.size();
calc_xpow(n);
hashing hs(s);
set<int> sizes;
forn(i, 0, m) {
if (!p[i]) continue;
int l = (i - 1 - p[i]) / 2;
int r = l + p[i];
sizes.insert(r-l);
ll value = hs.value(l, r);
palin[r-l].insert(value);
}
ll ans = 0;
for (auto &sz : sizes) {
int mx = 0;
map<ll, int> cnt;
forn(i, 0, n-sz+1) {
ll value = hs.value(i, i+sz);
if (palin[sz].count(value)) {
mx = max(mx, ++cnt[value]);
}
}
ans = max(ans, 1ll * mx * sz);
}
print(ans);
}
