#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pii;
#define all(x) x.begin(), x.end()
#define sz(x) ((int) ((x).size()))
#define pb push_back
#define F first
#define S second
#define FIO ios_base::sync_with_stdio(false); cin.tie(0)
struct Seg {
const static int off = 1 << 17;
ll tr[off * 2];
ll le[off * 2];
ll p[off * 2];
Seg() {
memset(tr, 0, sizeof tr);
memset(le, 0, sizeof le);
memset(p, 0, sizeof p);
}
void prop(int node, int x, int y) {
tr[node] += le[node] * (y - x + 1) + (y - x + 1) * (y - x + 2) / 2 * p[node];
if (x != y) {
p[node * 2] += p[node];
p[node * 2 + 1] += p[node];
le[node * 2] += le[node];
le[node * 2 + 1] += le[node] + (y - x + 1) / 2 * p[node];
}
le[node] = 0;
p[node] = 0;
}
void update(int l, int r, int node = 1, int x = 0, int y = off - 1) {
prop(node, x, y);
if (l > y or x > r) return;
if (l <= x and y <= r) {
p[node] += 1;
le[node] += x - l;
prop(node, x, y);
return;
}
update(l, r, node * 2, x, (x + y) / 2);
update(l, r, node * 2 + 1, (x + y) / 2 + 1, y);
tr[node] = tr[node * 2] + tr[node * 2 + 1];
}
ll query(int l, int r, int node = 1, int x = 0, int y = off - 1) {
if (l > y or x > r) return 0;
prop(node, x, y);
if (l <= x and y <= r) return tr[node];
return query(l, r, node * 2, x, (x + y) / 2) + query(l, r, node * 2 + 1, (x + y) / 2 + 1, y);
}
void updatei(int l, int r) {
update(off - r - 1, off - l - 1);
}
ll queryi(int l, int r) {
return query(off - r - 1, off - l - 1);
}
};
const int N = 1e5 + 10;
const int K = 30;
const int MOD1 = 1e9 + 7;
const int MOD2 = 1e9 + 9;
const int B1 = 31337;
const int B2 = 67;
ll potM(ll x, ll k, ll MOD) { if (k == 0) return 1; ll a = potM(x, k / 2, MOD); if (k % 2 == 0) { return (a * a) % MOD; } else { return ((a * a) % MOD * x) % MOD; }}
string s;
ll pot1[N];
ll pot2[N];
ll inv1[N];
ll inv2[N];
ll h1[N][2];
ll h2[N][2];
ll imp[N][K];
ll cur;
Seg u, ui;
pii hp(int l, int r) {
return {(h1[r + 1][0] - h1[l][0] + MOD1) % MOD1 * inv1[l] % MOD1, (h2[r + 1][0] - h2[l][0] + MOD2) % MOD2 * inv2[l] % MOD2};
}
pii hs(int l, int r) {
swap(l, r);
l = sz(s) - l - 1;
r = sz(s) - r - 1;
return {(h1[r + 1][1] - h1[l][1] + MOD1) % MOD1 * inv1[l] % MOD1, (h2[r + 1][1] - h2[l][1] + MOD2) % MOD2 * inv2[l] % MOD2};
}
int find(int c1, int c2) {
int l = 0;
int r = sz(s);
while (l < r) {
int mid = (l + r) / 2;
if (c1 - mid < 0 or c2 + mid >= sz(s) or hp(c1 - mid, c1) != hs(c2, c2 + mid)) {
r = mid;
} else {
l = mid + 1;
}
}
return l;
}
void run(int c1, int c2) {
int cnt = find(c1, c2);
if (cnt != 0) {
if (c1 == c2) {
if (cnt != 1) {
ui.updatei(c2 + 1, c2 + cnt - 1);
u.update(c1 - cnt + 1, c1 - 1);
}
} else {
ui.updatei(c2, c2 + cnt - 1);
u.update(c1 - cnt + 1, c1);
}
}
cur += cnt;
if (c1 - cnt >= 0 and c2 + cnt < sz(s)) {
imp[c1 - cnt][s[c2 + cnt] - 'a'] += find(c1 - cnt - 1, c2 + cnt + 1) + 1;
imp[c2 + cnt][s[c1 - cnt] - 'a'] += find(c1 - cnt - 1, c2 + cnt + 1) + 1;
}
}
int main() {
FIO;
pot1[0] = 1;
pot2[0] = 1;
inv1[0] = 1;
inv2[0] = 1;
for (int i = 1; i < N; i++) {
pot1[i] = (pot1[i - 1] * B1) % MOD1;
pot2[i] = (pot2[i - 1] * B2) % MOD2;
inv1[i] = potM(pot1[i], MOD1 - 2, MOD1);
inv2[i] = potM(pot2[i], MOD2 - 2, MOD2);
}
cin >> s;
for (int i = 0; i < sz(s); i++) {
h1[i + 1][0] = (h1[i][0] + pot1[i] * s[i]) % MOD1;
h2[i + 1][0] = (h2[i][0] + pot2[i] * s[i]) % MOD2;
}
for (int i = 0; i < sz(s); i++) {
h1[i + 1][1] = (h1[i][1] + pot1[i] * s[sz(s) - i - 1]) % MOD1;
h2[i + 1][1] = (h2[i][1] + pot2[i] * s[sz(s) - i - 1]) % MOD2;
}
for (int i = 0; i < sz(s); i++) {
run(i, i);
if (i + 1 < sz(s)) run(i, i + 1);
}
ll be = 0;
for (int i = 0; i < sz(s); i++) {
ll mi = -u.query(i, i) - ui.queryi(i, i);
for (int j = 0; j < K; j++) {
be = max(be, mi + imp[i][j]);
}
}
cout << cur + be << "\n";
return 0;
}
