#include <bits/stdc++.h>
using namespace std;
#define LL long long
#define mp make_pair
#define fi first
#define se second
string s;
char inp[300005];
int n;
int mo = 1e9 + 7;
int base = 16290047;
int base2 = 9999991;
int mo2 = 999999937;
int p_pow[300000 * 2 + 10];
int i_pow[300000 * 2 + 10];
int pfx[300000 * 2 + 10];
int p_pow2[300000 * 2 + 10];
int i_pow2[300000 * 2 + 10];
int pfx2[300000 * 2 + 10];
map < pair < int , int > , int > occ;
map < pair < int , int > , pair < int , int > > dp[300000* 2+ 10];
int expo(int a, int b){
if ( b == 0 ) return 1;
int half = expo(a,b/2);
half = ( 1LL * half * half ) % mo;
if ( b & 1 ) half = (1LL * half * a ) % mo;
return half;
}
int expo2(int a, int b){
if ( b == 0 ) return 1;
int half = expo2(a,b/2);
half = ( 1LL * half * half ) % mo2;
if ( b & 1 ) half = (1LL * half * a ) % mo2;
return half;
}
int h( int l, int r ){
int ans = pfx[r] - pfx[l];
if ( ans < 0 ) ans += mo;
ans = ( ans * 1LL * i_pow[l] ) % mo;
return ans;
}
int h2( int l, int r ){
int ans = pfx2[r] - pfx2[l];
if ( ans < 0 ) ans += mo2;
ans = ( ans * 1LL * i_pow2[l] ) % mo2;
return ans;
}
vector < int > manacher_odd(string s){
vector < int > p(s.size(), 0);
int l = 1, r = 1;
for ( int i = 1; i <= s.size()-2; i++ ){
p[i] = max(0, min(r-i, p[l + (r-i)]) );
while ( s[i-p[i]] == s[i+p[i]] ){
p[i]++;
}
if ( i + p[i] > r ){
l = i - p[i];
r = i + p[i];
}
}
return p;
}
LL solve1(){
s = inp;
s = "$" + s + "^";
vector < int > p = manacher_odd(s);
int N = s.size() - 2;
for ( int i = 0; i < s.size(); i++ ){
pfx[i] = (s[i] * 1LL * p_pow[i]) % mo;
if ( i ) pfx[i] += pfx[i-1];
if ( pfx[i] >= mo ) pfx[i] -= mo;
pfx2[i] = (s[i] * 1LL * p_pow2[i]) % mo2;
if ( i ) pfx2[i] += pfx2[i-1];
if ( pfx2[i] >= mo2 ) pfx2[i] -= mo2;
}
// p[i] * 2 - 1
LL ans = 0;
for ( int i = 1; i <= N; i++ ){
int l = i - p[i], r = i + p[i];
auto it = make_pair(h(l,r-1),h2(l,r-1));
if ( occ.find(it) == occ.end() ) dp[p[i]][it] = mp(l,r-1);
++occ[it];
}
for ( int i = s.size(); i >= 1; i-- ){
for ( auto it : dp[i] ){
auto ff = it.fi, ss = it.se;
ans = max( ans, occ[ff] * 1LL * (i * 2 - 1));
if ( ss.fi + 1 < ss.se - 1 ){
auto enc = mp(h(ss.fi+1,ss.se-1), h2(ss.fi+1,ss.se-1));
if ( occ.find(enc) == occ.end() ) dp[i-1][enc] = mp(ss.fi+1,ss.se-1);
occ[enc] += occ[ff];
}
}
}
return ans;
}
LL solve2(){
s = "$";
for ( int i = 0; i < n; i++ ){
s += "#";
s += inp[i];
}
s += "#^";
vector < int > p = manacher_odd(s);
int N = s.size()-2;
for ( int i = 0; i < s.size(); i++ ){
pfx[i] = (s[i] * 1LL * p_pow[i]) % mo;
if ( i ) pfx[i] += pfx[i-1];
if ( pfx[i] >= mo ) pfx[i] -= mo;
pfx2[i] = (s[i] * 1LL * p_pow2[i]) % mo2;
if ( i ) pfx2[i] += pfx2[i-1];
if ( pfx2[i] >= mo2 ) pfx2[i] -= mo2;
}
LL ans = 0;
for ( int i = 1; i <= N; i++ ){
if ( s[i] == '#' ){
int l = i - p[i], r = i + p[i];
auto it = make_pair(h(l,r-1),h2(l,r-1));
if ( occ.find(it) == occ.end() ) dp[p[i]][it] = mp(l,r-1);
++occ[it];
}
}
for ( int i = s.size(); i > 1; i-- ){
for ( auto it : dp[i] ){
auto ff = it.fi, ss = it.se;
ans = max( ans, occ[ff] * 1LL * (i-1));
if ( ss.fi + 2 < ss.se - 2 ){
auto enc = mp(h(ss.fi+2,ss.se-2), h2(ss.fi+2,ss.se-2));
if ( occ.find(enc) == occ.end() ) dp[i-2][enc] = mp(ss.fi+2,ss.se-2);
occ[enc] += occ[ff];
}
}
}
return ans;
}
int main(){
scanf("%s",&inp);
n = strlen(inp);
int p = 1;
for ( int i = 0; i <= (n + 3) * 2; i++ ){
p_pow[i] = p;
p = (p * 1LL * base) % mo;
}
int inv = expo(base,mo-2);
int ip = 1;
for ( int i = 0; i <= (n+3) * 2 ; i++ ){
i_pow[i] = ip;
ip = (1LL * ip * inv) % mo;
}
p = 1;
for ( int i = 0; i <= (n + 3) * 2; i++ ){
p_pow2[i] = p;
p = (p * 1LL * base2) % mo2;
}
inv = expo2(base2,mo2-2);
ip = 1;
for ( int i = 0; i <= (n+3) * 2 ; i++ ){
i_pow2[i] = ip;
ip = (1LL * ip * inv) % mo2;
}
LL ans1 = solve1();
occ.clear();
for ( int i = 0; i <= (n+3) * 2; i++ ){
dp[i].clear();
}
LL ans2 = solve2();
if ( ans1 > ans2 ) printf("%lld\n",ans1);
else printf("%lld\n",ans2);
return 0;
}
