#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef double dou;
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back
#define BITJ(x, j) (((x)>>(j))&1)
#define MASK(j) (1LL<<(j))
#define ALL(v) v.begin(), v.end()
template<typename T> bool maximize(T &x, const T &y) {
if (x < y) {x = y; return 1;}
return 0;
}
template<typename T> bool minimize(T &x, const T &y) {
if (x > y) {x = y; return 1;}
return 0;
}
namespace modulofunc{
const int mod = 998244353;
int add(int x, int y) {
return (mod-x <= y ? x-mod+y : x+y);
}
void addt(int &x, int y) {
x = add(x, y);
}
int sub(int x, int y) {
return (x-y < 0 ? x-y+mod : x-y);
}
void subt(int &x, int y) {
x = sub(x, y);
}
int mul(int x, int y) {
return 1LL*x*y%mod;
}
int binpow(int x, int k) {
int res = 1;
while (k > 0 ){
if (k&1) res = mul(res, x);
x = mul(x, x);
k >>= 1;
}
return res;
}
}
using namespace modulofunc;
const int maxn = 1e5+5;
int n;
string s;
namespace sub3{
const int base = 31;
int pw[maxn], prefh[maxn][2];
void setup() {
pw[0] = 1;
for (int i= 1; i < maxn; i++) {
pw[i] = mul(pw[i-1], base);
// if (i < 7) cout << pw[i] << ' ';
}
// cout << "\n";
prefh[0][0] = 0;
for (int i = 1; i <= n; i++) {
prefh[i][0] = add(mul(prefh[i-1][0], base), (int)(s[i]-'a'+1));
}
prefh[n+1][1] = 0;
for (int i = n; i; i--) {
prefh[i][1] = add(mul(prefh[i+1][1], base), (int)(s[i]-'a'+1));
}
// cout << "here comes all prefh\n";
// for (int i = 1; i <= n; i++) {
// cout << prefh[i][0] << ' ';
// }
// cout << "\n";
// for (int i = 1; i <= n; i++) {
// cout << prefh[i][1] << ' ';
// }
// cout << "\n";
}
int gethash(int l, int r, bool rev) {
int val;
if (rev) val = sub(prefh[l][1], mul(prefh[r+1][1], pw[r-l+1]));
else val = sub(prefh[r][0], mul(prefh[l-1][0], pw[r-l+1]));
// cout << "gethash " << l << ' ' << r << ' ' << rev << ": " << val << "\n";
return val;
}
struct segment{
int l, r;
bool inmid;
segment(int _l, int _r, bool _inmid) {
l = _l;
r = _r;
inmid = _inmid;
}
};
vector<segment> realseg;
ll incdelta[maxn], stadelta[maxn]; //delta encoding
ll preans;
ll anschange[maxn][26];
ll ans;
void construct_boundaries() {
//setup boundaries
//also calculate preans
preans = 0;
for (int i = 1; i <= n; i++) {
//on element
//bound of starting segment would be the mid
int len = 0;
for (int cnt = n>>1; cnt > 0; cnt >>= 1 ){
while (len+cnt <= min(n-i, i-1) &&
gethash(i-(len+cnt), i, 1) == gethash(i, i+(len+cnt), 0)) {
len += cnt;
}
}
//segments: i-len, i+len
realseg.pb(segment(i-len, i+len, 0));
preans += len+1;
// cout << "on ele " << i << ' ' << len+1 << "\n";
}
for (int i = 1; i < n; i++) {
//in mid
int len = 0;
for (int cnt = n>>1; cnt > 0; cnt >>= 1) {
while (cnt+len <= min(i, n-i) &&
gethash(i-(len+cnt)+1, i, 1) == gethash(i+1, i+(len+cnt), 0)) {
len += cnt;
}
}
//segment: i-len+1, i+len
realseg.pb(segment(i-len+1, i+len, 1));
preans += len;
// cout << "in mid " << i << ' ' << len << "\n";
}
ans = preans;
}
int check_further(int l, int r) {
if (l < 1 || r > n) return 0;
int len = 0;
for (int cnt = n>>1; cnt > 0; cnt >>= 1){
while (len+cnt <= min(l, n-r+1) &&
gethash(l-(len+cnt)+1, l, 1) == gethash(r, r+(len+cnt)-1, 0)) {
len += cnt;
}
}
return len;
}
void solve() {
setup();
construct_boundaries();
memset(anschange, 0, sizeof(anschange));
memset(incdelta, 0, sizeof(incdelta));
memset(stadelta, 0, sizeof(stadelta));
//case add
for (segment cur : realseg) {
int l = cur.l, r = cur.r;
//delta encoding
int mid = (l+r)>>1;
if (cur.inmid) {
if (r-l > 0) {
//inmid
incdelta[l-1]++;
incdelta[mid]--;
incdelta[mid+1]--;
incdelta[r]++;
}
}
else if (r-l > 1) {
//in ele
//->0<-
incdelta[l-1]++;
incdelta[mid-1]--;
stadelta[mid-1] = l-mid;
stadelta[mid] = mid-l;
incdelta[mid+1]--;
incdelta[r]++;
}
//eligible
if (l <= 1 || r >= n) continue;
//change left
//change right
int val = check_further(l-2, r+2)+1;
// cout << "[] segment " << l << ' ' << r << ' ' << val << "\n";
anschange[l-1][s[r+1]-'a'] += val;
anschange[r+1][s[l-1]-'a'] += val;
}
//case minus
//resolve encoding to ans
ll curcou = 0, curinc = incdelta[0];
for (int i = 1; i <= n; i++) {
curcou += curinc;
//fixed for i
for (int c = 0; c < 26; c++) {
anschange[i][c] -= curcou;
//maximize ans
maximize(ans, preans + anschange[i][c]);
}
curcou += stadelta[i];
curinc += incdelta[i];
}
cout << ans;
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
// #define name "task"
// if (fopen(name".inp", "r")) {
// freopen(name".inp", "r", stdin);
// freopen(name".out", "w", stdout);
// }
cin >> s;
n = (int)s.size();
s = "#"+s;
return sub3::solve(), 0;
}
/*
aaaa
10
baccb
9
slavko
7
*/
