#include<bits/stdc++.h>
using namespace std;
string substring(string s,int a,int b)
{
string s1="";
for(int i = a; i < b; i++)
s1 = s1 + s[i];
return s1;
}
vector<string> allPalindromeSubstring(string s)
{
vector<string> v ;
for (float pivot = 0; pivot < s.length();
pivot += .5)
{
float palindromeRadius = pivot -
(int)pivot;
while ((pivot + palindromeRadius)
< s.length() && (pivot - palindromeRadius)
>= 0 && s[((int)(pivot - palindromeRadius))]
== s[((int)(pivot + palindromeRadius))])
{
v.push_back(substring(s,(int)(pivot -
palindromeRadius), (int)(pivot
+ palindromeRadius + 1)));
palindromeRadius++;
}
}
return v;
}
vector<int> rabin_karp(string const& s, string const& t) {
const int p = 31;
const int m = 1e9 + 9;
int S = s.size(), T = t.size();
vector<long long> p_pow(max(S, T));
p_pow[0] = 1;
for (int i = 1; i < (int)p_pow.size(); i++)
p_pow[i] = (p_pow[i-1] * p) % m;
vector<long long> h(T + 1, 0);
for (int i = 0; i < T; i++)
h[i+1] = (h[i] + (t[i] - 'a' + 1) * p_pow[i]) % m;
long long h_s = 0;
for (int i = 0; i < S; i++)
h_s = (h_s + (s[i] - 'a' + 1) * p_pow[i]) % m;
vector<int> occurences;
for (int i = 0; i + S - 1 < T; i++) {
long long cur_h = (h[i+S] + m - h[i]) % m;
if (cur_h == h_s * p_pow[i] % m)
occurences.push_back(i);
}
return occurences;
}
int main()
{
string a;
cin>>a;
vector<string> v = allPalindromeSubstring(a);
set<string>aw;
for(auto it:v)aw.insert(it);
int ans=0;
for(auto it:aw)
{
ans=max(ans,(int)((rabin_karp(it,a).size())*it.size()));
}
cout<<ans;
}
