#include <bits/stdc++.h>
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;
const ld eps=1e-7;
const int inf=1000000010;
const ll INF=10000000000000010LL;
const int mod = 1000000007;
const int MAXN = 100010, B=10007;
ll n, m, k, u, v, x, y, t, a, b, ans, pal;
char A[MAXN];
ll hl[MAXN], hr[MAXN], tav[MAXN];
ll ps1[MAXN];
ll cnt[MAXN][26];
ll getl(int l, int r){
ll res=(hl[r]-hl[l-1]*tav[r-l+1])%mod;
return (res+mod)%mod;
}
ll getr(int l, int r){
ll res=(hr[l]-hr[r+1]*tav[r-l+1])%mod;
return (res+mod)%mod;
}
bool check(int l1, int r1, int l2, int r2){
if (min(l1, l2)<1 || n<max(r1, r2)) return 0;
//debug("shit")
return getl(l1, r1)==getr(l2, r2);
}
int main(){
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
string s;
cin>>s;
n=s.size();
for (int i=1; i<=n; i++) A[i]=s[i-1];
for (int i=1; i<=n; i++) hl[i]=(hl[i-1]*B+A[i])%mod;
for (int i=n; i; i--) hr[i]=(hr[i+1]*B+A[i])%mod;
tav[0]=1;
for (int i=1; i<=n; i++) tav[i]=tav[i-1]*B%mod;
/*
// ---------------------------------------------------
for (int i=0; i<=n; i++) cerr<<hl[i]<<" \n"[i==n];
debug(check(1, 1, 2, 2))
debug(getl(1, 1))
debug(getl(2, 2))
*/
/// even lenth
for (int i=1; i<=n; i++){
int dwn=0, up=n+1;
while (up-dwn>1){
int mid=(dwn+up)>>1;
if (check(i-mid+1, i, i+1, i+mid)) dwn=mid;
else up=mid;
}
int len=dwn, l=i-len+1, r=i+len;
//debug2(i, len)
if (len){
ps1[l]++;
ps1[i+1]--;
ps1[i+2]--;
ps1[r+2]++;
//debug2(l, r)
}
// tof can be deleted
pal+=len;
if (l<=1 || r>=n) continue ;
dwn=0, up=n;
while (up-dwn>1){
int mid=(dwn+up)>>1;
if (check(l-1-mid, l-2, r+2, r+1+mid)) dwn=mid;
else up=mid;
}
cnt[l-1][A[r+1]-'a']+=dwn+1;
cnt[r+1][A[l-1]-'a']+=dwn+1;
}
// odd lenth
for (int i=1; i<=n; i++){
int dwn=0, up=n+1;
while (up-dwn>1){
int mid=(dwn+up)>>1;
if (check(i-mid, i-1, i+1, i+mid)) dwn=mid;
else up=mid;
}
int len=dwn, l=i-len, r=i+len;
//debug2(i, len)
ps1[l]++;
ps1[i]-=len+1;
ps1[i+1]+=len*2;
ps1[i+2]-=len+1;
ps1[r+2]++;
pal+=len+1;
if (l<=1 || r>=n) continue ;
dwn=0, up=n;
while (up-dwn>1){
int mid=(dwn+up)>>1;
if (check(l-1-mid, l-2, r+2, r+1+mid)) dwn=mid;
else up=mid;
}
cnt[l-1][A[r+1]-'a']+=dwn+1;
cnt[r+1][A[l-1]-'a']+=dwn+1;
}
// ----------
for (int i=1; i<=n; i++) ps1[i]+=ps1[i-1];
for (int i=1; i<=n; i++) ps1[i]+=ps1[i-1];
//for (int i=1; i<=n; i++) cerr<<ps1[i]<<" \n"[i==n];
ans=pal;
for (int i=1; i<=n; i++) for (int c=0; c<26; c++) ans=max(ans, pal-ps1[i]+cnt[i][c]);
cout<<ans<<'\n';
return 0;
}
