#include<bits/stdc++.h>
#define ll long long
#define int long long
const int nmax = 3e5 + 5;
const ll oo = 1e18;
const int lg = 20;
const int base = 4000;
const ll mod = 1e9 + 7;
#define pii pair<int, int>
#define fi first
#define se second
#define int long long
#define debug(a, n) for(int i = 1; i <= n; ++i) cout << a[i] << ' ';
using namespace std;
int n, cur = 0;
string s;
int pw[nmax], h[nmax], rh[nmax];
void Init(){
pw[0] = 1;
for(int i = 1; i <= n; ++i){
pw[i] = pw[i - 1] * base % mod;
h[i] = (h[i - 1] * base + s[i] - 'a' + 1) % mod;
}
reverse(s.begin(), s.end());
for(int i = 1; i <= n; ++i) rh[i] = (rh[i - 1] * base + s[i] - 'a' + 1) % mod;
reverse(s.begin(), s.end());
}
int get(int l, int r, int h[]){
return (h[r] - h[l - 1] * pw[r - l + 1] + mod * mod) % mod;
}
bool check(int l, int r){
return get(l, r, h) == get(n - r + 1, n - l + 1, rh);
}
map<int, int> mp, f, par, ind;
int cnt[nmax];
void update(int l, int r){
int u = l, v = r;
bool ok = 1;
while(l <= r){
int x = get(l, r, h);
if(++mp[x] == 1){
ind[x] = ++cur;
if(ok){
f[cur]++;
ok = 0;
}
cnt[cur] = r - l + 1;
if(l + 1 <= r - 1){
par[x] = get(l + 1, r - 1, h);
}
}
else{
if(ok){
int id = ind[x];
f[id]++;
}
break;
}
++l, --r;
}
}
vector<int> adj[nmax];
void dfs(int u){
for(auto v : adj[u]){
dfs(v);
f[u] += f[v];
}
}
main(){
ios_base::sync_with_stdio(0);
// cin.tie(0);cout.tie(0);
// freopen("code.inp", "r", stdin);
// freopen("code.out", "w", stdout);
cin >> s;
n = s.size(); s = ' ' + s + ' ';
Init();
for(int i = 1; i <= n; ++i){
int l = 1, r = min(i, n - i + 1), kq = 1;
while(l <= r){
int mid = r + l >> 1;
if(check(i - mid + 1, i + mid - 1)){
kq = mid;
l = mid + 1;
}
else r = mid - 1;
}
update(i - kq + 1, i + kq - 1);
l = 1, r = min(i, n - i), kq = -1;
while(l <= r){
int mid = r + l >> 1;
if(check(i - mid + 1, i + mid)){
kq = mid;
l = mid + 1;
}
else r = mid - 1;
}
if(kq != -1) update(i - kq + 1, i + kq);
}
for(auto [x, y] : mp){
int v = ind[x];
int u = ind[par[x]];
adj[u].push_back(v);
}
dfs(0);
ll ans = 0;
for(int i = 1; i <= cur; ++i){
// cout << f[i]
ans = max(ans, f[i] * cnt[i]);
}
cout << ans;
}
/*
*/
