#include<bits/stdc++.h>
using namespace std;
#define all(x) x.begin() , x.end()
#define sze(x) (ll)(x.size())
typedef long long ll;
typedef pair<ll , ll> pll;
const ll maxn = 3e5 + 16 , P = 131 , md = 2000000357 , inf = 2e16;
struct mintree {
ll sz = 1;
vector<pll> val;
pll def;
void init(ll n){
while(sz < n) sz <<= 1;
def = {inf , -1};
val.assign(sz << 1 , def);
return;
}
void build(vector<ll> &a , ll x , ll lx , ll rx){
if(rx - lx == 1){
if(lx < sze(a)){
val[x] = {a[lx] , lx};
}
return;
}
ll m = (rx + lx) >> 1 , ln = (x << 1) + 1 , rn = ln + 1;
build(a , ln , lx , m); build(a , rn , m , rx);
val[x] = min(val[ln] , val[rn]);
}
void build(vector<ll> &a){
build(a , 0 , 0 , sz);
return;
}
pll cal(ll l , ll r , ll x , ll lx , ll rx){
if(rx <= l || lx >= r) return def;
if(rx <= r && lx >= l) return val[x];
ll m = (rx + lx) >> 1 , ln = (x << 1) + 1 , rn = ln + 1;
pll a = cal(l , r , ln , lx , m) , b = cal(l , r , rn , m , rx);
return min(a , b);
}
pll cal(ll l , ll r){
return cal(l , r , 0 , 0 , sz);
}
};
struct segtree {
ll sz = 1;
vector<ll> val;
void init(ll n){
while(sz < n) sz <<= 1;
val.assign(sz << 1 , inf);
return;
}
void set(ll i , ll k , ll x , ll lx , ll rx){
if(rx - lx == 1){
val[x] = k;
return;
}
ll m = (rx + lx) >> 1 , ln = (x << 1) + 1 , rn = ln + 1;
if(i < m){
set(i , k , ln , lx , m);
} else {
set(i , k , rn , m , rx);
}
val[x] = min(val[ln] , val[rn]);
return;
}
void set(ll i , ll k){
set(i , k , 0 , 0 , sz);
return;
}
ll cal(ll l , ll r , ll k , ll x , ll lx , ll rx){
if(rx <= l || lx >= r) return -1;
if(val[x] > k) return -1;
if(rx - lx == 1) return lx;
ll m = (rx + lx) >> 1 , ln = (x << 1) + 1 , rn = ln + 1;
ll a = cal(l , r , k , rn , m , rx);
if(a != -1) return a;
return cal(l , r , k , ln , lx , m);
}
ll cal(ll l , ll r , ll k){
return cal(l , r , k , 0 , 0 , sz);
}
};
ll n;
string s;
mintree mt;
segtree st[2];
ll sf[maxn] , hs[maxn] , rh[maxn] , tv[maxn];
vector<ll> lcp;
ll hum = -1;
ll get_hash(ll l , ll r){
if(r >= n) return hum--;
ll res = hs[r] - (l ? tv[r - l + 1] * hs[l - 1] : 0);
res %= md; res += (res < 0) * md;
return res;
}
bool is_palindrome(ll l , ll r){
if(l < 0 || r >= n) return false;
ll h = hs[r] - (l ? tv[r - l + 1] * hs[l - 1] : 0);
h %= md; h += (h < 0) * md;
ll o = rh[r] - (l ? rh[l - 1] : 0);
o %= md; o += (o < 0) * md;
h *= tv[l]; h %= md;
return (h == o);
}
ll get_lcp(ll i , ll j){
ll l = 0 , r = n;
while(l < r - 1){
ll m = (r + l) >> 1;
if(get_hash(i , i + m - 1) == get_hash(j , j + m - 1)){
l = m;
} else {
r = m;
}
}
return l;
}
ll t[maxn][2];
ll query(ll i , ll k){
if(k < 2) return k;
ll res = 0;
ll l = i , r = i + (k + 1) / 2;
ll h = st[0].cal(l , r , i);
if(h != -1){
res = max(res , 2 * (h - i) + 1);
}
r = i + k / 2;
h = st[1].cal(l , r , i);
// cout<<l<<' '<<r<<' '<<i<<' '<<t[l][1]<<' '<<h<<'\n';
if(h != -1){
res = max(res , 2 * (h - i) + 2);
}
return res;
}
ll ans = 0;
void dv(ll l , ll r){
if(l == r - 1){
ans = max(ans , query(sf[l] , n - sf[l]));
}
if(l >= r - 1) return;
pll h = mt.cal(l , r - 1);
ll k = h.first , m = h.second + 1;
ans = max(ans , (r - l) * query(sf[l] , k));
dv(l , m); dv(m , r);
return;
}
ll rnk[maxn] , rhk[maxn];
vector<pll> cnt[maxn] , v;
ll cal_t(ll i , bool j){
ll l = -1 , r = i + j;
while(l < r - 1){
ll m = (r + l) >> 1;
if(is_palindrome(m , i + i - m + j)){
r = m;
} else {
l = m;
}
}
return r;
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
tv[0] = 1;
for(ll i = 1 ; i < maxn ; i++){
tv[i] = tv[i - 1] * P % md;
}
cin>>s; n = sze(s);
for(ll i = 0 ; i < n ; i++){
rnk[i] = s[i] - 'a' + 1;
}
ll lm = max(27ll , n + 1);
for(ll j = 0 ; j < 20 ; j++){
v.clear();
for(ll i = 0 ; i < lm ; i++){
cnt[i].clear(); cnt[i].shrink_to_fit();
}
for(ll i = 0 ; i < n ; i++){
ll o = i + (1 << j);
rhk[i] = (o >= n ? 0 : rnk[o]);
cnt[rhk[i]].push_back({rnk[i] , i});
}
for(ll i = 0 ; i < lm ; i++){
for(auto p : cnt[i]){
v.push_back(p);
}
}
for(ll i = 0 ; i < lm ; i++){
cnt[i].clear(); cnt[i].shrink_to_fit();
}
for(auto p : v){
ll i = p.second;
cnt[rnk[i]].push_back({rhk[i] , i});
}
ll cur = 0;
for(ll e = 0 ; e < lm ; e++){
ll pr = -1;
for(auto p : cnt[e]){
ll i = p.second , u = p.first;
if(pr != u){
cur++; pr = u;
}
rnk[i] = cur;
}
}
}
for(ll i = 0 ; i < n ; i++){
sf[rnk[i] - 1] = i;
}
rh[0] = hs[0] = s[0];
for(ll i = 1 ; i < n ; i++){
hs[i] = P * hs[i - 1] + s[i]; hs[i] %= md;
rh[i] = rh[i - 1] + tv[i] * s[i]; rh[i] %= md;
}
lcp.resize(n - 1);
for(ll e = 0 ; e < n - 1 ; e++){
lcp[e] = get_lcp(sf[e] , sf[e + 1]);
}
st[0].init(n); st[1].init(n);
for(ll i = 0 ; i < n ; i++){
t[i][0] = cal_t(i , 0);
st[0].set(i , t[i][0]);
t[i][1] = cal_t(i , 1);
st[1].set(i , t[i][1]);
}
mt.init(n);
mt.build(lcp);
dv(0 , n);
cout<<ans<<'\n';
return 0;
}
