// made by Tima
// 2025 will be a golden year...
#include "bits/stdc++.h"
#include <ext/pb_ds/assoc_container.hpp>
#define ll long long
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define int long long
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
#define pii pair<int,int>
#define tpii pair <pair <int,int> , int>
#define bruh cout << "NO\n"
using namespace std;
using namespace __gnu_pbds;
const int N = 3e5 + 5;
int mod = 1e9 + 7;
const int INF = 1e18;
int n;
string s;
void Gold(){
cin >> s;
s = '=' + s;
n = s.size() - 1;
int ans = 0;
map <string , int> mp;
for(int i = 1 ; i <= n ; i++){
for(int j = i ; j <= n ; j++){
int l = i , r = j;
bool oknt = 0;
string cur = "";
while(l < r){
if(s[l] != s[r]){
oknt = 1;
break;
}
l++;
r--;
}
for(int k = i ; k <= j ; k++){
cur.pb(s[k]);
}
if(!oknt){
mp[cur]++;
}
}
}
for(auto it : mp){
ans = max(ans , (ll)it.S * (ll)(it.F).size());
}
cout << ans;
}
//https://codeforces.com/blog/entry/133289
signed main(/*Zhunussov Temirlan*/){
//freopen("txt.in","r",stdin);freopen("txt.out","w",stdout);
ios_base::sync_with_stdio(0);cin.tie(0);
srand(time(0));
int TT = 1;
// cin >> TT;
for(int i = 1 ; i <= TT ; i++){
//cout << "Case " << i << ": ";
Gold();
}
}
