#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<int MOD>
struct ModInt {
unsigned x;
ModInt() : x(0) { }
ModInt(signed sig) : x(sig%MOD) { }
ModInt(signed long long sig) : x(sig%MOD) { }
int get() const { return (int)x; }
ModInt pow(long long p) { ModInt res = 1, a = *this; while (p) { if (p & 1) res *= a; a *= a; p >>= 1; } return res; }
ModInt &operator+=(ModInt that) { if ((x += that.x) >= MOD) x -= MOD; return *this; }
ModInt &operator-=(ModInt that) { if ((x += MOD - that.x) >= MOD) x -= MOD; return *this; }
ModInt &operator*=(ModInt that) { x = (unsigned long long)x * that.x % MOD; return *this; }
ModInt &operator/=(ModInt that) { return (*this) *= that.pow(MOD - 2); }
ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
ModInt operator/(ModInt that) const { return ModInt(*this) /= that; }
bool operator<(ModInt that) const { return x < that.x; }
friend ostream& operator<<(ostream &os, ModInt a) { os << a.x; return os; }
};
#define endl '\n'
#define mod 1000000007
#define sz(x) ((int)x.size())
#define all(a) (a).begin(), (a).end()
typedef long long ll;
typedef long double ld;
typedef ModInt<mod> mint;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
string FileS="";
bool tstc=0;
void dothethingythatfindsthesolutiontotheproblem(){
string s;
cin>>s;
map<deque<char>,ll>mp;
ll ans=0;
for(int i=0;i<sz(s);i++){
deque<char>dq;
for(int w=i;w<sz(s);w++){
dq.push_back(s[w]);
mp[dq]++;
}
}
for(int i=0;i<sz(s);i++){
int l=i,r=i;
deque<char>dq;
while(l>=0&&r<sz(s)&&s[l]==s[r]){
dq.push_back(s[r]);
if(l!=r)dq.push_front(s[l]);
ans=max(ans,mp[dq]*sz(dq));
r++;
l--;
}
}
for(int i=1;i<sz(s);i++){
int l=i-1,r=i;
deque<char>dq;
while(l>=0&&r<sz(s)&&s[l]==s[r]){
dq.push_back(s[r]);
if(l!=r)dq.push_front(s[l]);
ans=max(ans,mp[dq]*sz(dq));
r++;
l--;
}
}
cout<<ans;
}
void File(){
ifstream cin(FileS + ".in");
ofstream cout(FileS + ".out");
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
if(FileS.size())File();
int tc=1;
if(tstc)cin>>tc;
while(tc--){
dothethingythatfindsthesolutiontotheproblem();
}
}
