//Designed by SabirM
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define fastio ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
const int INF = 1e18;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
bool ok(string &s){
string a=s;
reverse(a.begin(),a.end());
return a==s;
}
signed main(){
fastio;
string s;
cin>>s;
int n=s.size();
vector<int> freq;
int cnt=0;
for(int i=0;i<n;i++){
string a="";
for(int j=i;j<n;j++){
a+=s[j];
if(ok(a)){
cnt++;
}
}
}
freq.pb(cnt);
for(int i=0;i<26;i++){
for(int j=0;j<n;j++){
char og=s[j];
s[j]=char('a'+i);
//cout<<s<<" ";
int cnt1=0;
for(int z=0;z<n;z++){
string a="";
for(int d=z;d<n;d++){
a+=s[d];
if(ok(a)){
cnt1++;
}
}
}
freq.pb(cnt1);
//cout<<cnt1<<"\n";
s[j]=og;
}
}
sort(freq.begin(),freq.end());
cout<<freq[freq.size()-1]<<"\n";
}
