#include <bits/stdc++.h>
//#define int long long
#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(lmao) lmao.begin(), lmao.end()
using namespace std;
typedef pair<ll, ll> pii;
const int N = 3e5 + 5;
const int M = 1e6 + 5;
const ll oo = 1e16;
int n, a[N];
int pos[N], sa[N], gap, tmp[N], lcp[N], LG[N], dp[22][N];
ll ans = 0;
bool cmp(int x,int y){
if(pos[x] != pos[y]) return pos[x] < pos[y];
x += gap;
y += gap;
return (x <= n && y <= n ? pos[x] < pos[y] : x > y);
}
void SA(){
gap = 1;
for(int i = 1; i <= n; i ++) pos[i] = a[i], sa[i] = i;
while(true){
sort(sa + 1, sa + n + 1, cmp);
for(int i = 2; i <= n; i ++) tmp[i] = tmp[i - 1] + cmp(sa[i - 1], sa[i]);
for(int i = 1; i <= n; i ++) pos[sa[i]] = tmp[i] + 1;
if(tmp[n] == n - 1) break;
gap = gap * 2;
}
for(int i = 1, k = 0; i <= n; i ++){
if(pos[i] == n) continue;
for(int j = sa[pos[i] + 1]; a[i + k] == a[j + k]; ) k ++;
lcp[pos[i]] = k;
if(k) k--;
}
for(int i = 1; i <= n; i ++) LG[i] = (i == 1 ? 0 : LG[i / 2] + 1);
for(int i = n; i >= 1; i --){
dp[0][i] = lcp[i];
for(int j = 1; j <= 20 && i + (1 << j) - 1 <= n; j ++){
dp[j][i] = min(dp[j - 1][i], dp[j - 1][i + (1 << (j - 1))]);
}
}
}
int kq[2][N];
namespace Hash{
#define int long long
mt19937 rd(2615367263);
int ra(int l,int r){
return l + rd() % (r - l + 1);
}
const int MOD[2] = {ra(1e9, 2e9), (int)1e9 + 7};
const int base = 137;
int pw[2][N], h[2][N], g[2][N];
int get(int l,int r){
int A = (h[0][r] + MOD[0] - h[0][l - 1] * pw[0][r - l + 1] % MOD[0]) % MOD[0];
int B = (h[1][r] + MOD[1] - h[1][l - 1] * pw[1][r - l + 1] % MOD[1]) % MOD[1];
return A * MOD[1] + B;
}
int rev(int l,int r){
int A = (g[0][l] + MOD[0] - g[0][r + 1] * pw[0][r - l + 1] % MOD[0]) % MOD[0];
int B = (g[1][l] + MOD[1] - g[1][r + 1] * pw[1][r - l + 1] % MOD[1]) % MOD[1];
return A * MOD[1] + B;
}
void solve(){
pw[0][0] = pw[1][0] = 1;
for(int i = 1; i <= n; i ++) for(int j = 0; j <= 1; j ++){
pw[j][i] = pw[j][i - 1] * base % MOD[j];
h[j][i] = (h[j][i - 1] * base % MOD[j] + a[i]) % MOD[j];
}
for(int i = n; i >= 1; i --) for(int j = 0; j <= 1; j ++) {
g[j][i] = (g[j][i + 1] * base % MOD[j] + a[i]) % MOD[j];
}
for(int i = 1; i <= n; i ++){
int l = 1, r = min(n - i, i);
while(l <= r) {
int mid = (l + r) / 2;
if(get(i - mid + 1, i) == rev(i + 1, i + mid)){
kq[0][i] = mid;
l = mid + 1;
}else r = mid - 1;
}
l = 1, r = min(n - i + 1, i);
while(l <= r) {
int mid = (l + r) / 2;
// if(i == 4) {
// cerr << i - mid + 1 << " " << i << " " << get(i - mid + 1, i) << " h\n";
// cerr << i << " " << i + mid - 1
// }
if(get(i - mid + 1, i) == rev(i, i + mid - 1)){
kq[1][i] = mid;
l = mid + 1;
}else r = mid - 1;
}
}
}
}
int query(int l,int r){
int k = LG[r - l + 1];
return min(dp[k][l], dp[k][r - (1 << k) + 1]);
}
int bs(int x, int len){
int i = pos[x];
int l = 1, r = i - 1, _left = i;
while(l <= r){
int mid = (l + r) / 2;
if(query(mid, i - 1) >= len){
_left = mid;
r = mid - 1;
}else l = mid + 1;
}
l = i, r = n - 1;
int _right = i;
while(l <= r) {
int mid = (l + r) / 2;
if(query(i, mid) >= len){
_right = mid + 1;
l = mid + 1;
}else r = mid - 1;
}
return _right - _left + 1;
}
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define task "v"
if(fopen(task ".inp","r")){
freopen(task ".inp","r",stdin);
freopen(task ".out","w",stdout);
}
string s; cin >> s;
n = s.size(); s = " " + s;
for(int i = 1; i <= n; i ++) a[i] = (int)(s[i] - 'a') + 1;
SA();
Hash :: solve();
for(int i = 1; i <= n; i ++){
if(kq[0][i]){
int tmp = bs(i - kq[0][i] + 1, 2 * kq[0][i]);
ans = max(ans, 1ll * tmp * 2 * kq[0][i]);
}
if(kq[1][i]){
int tmp = bs(i - kq[1][i] + 1, 2 * kq[1][i] - 1);
ans = max(ans, 1ll * tmp * (2 * kq[1][i] - 1));
}
}
cout << ans;
}
