#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define sz(v) (int)v.size()
#define x first
#define y second
#define nl "\n"
using namespace std;
const int N = (int)1e3 + 7;
const int M = (int)2e6 + 5e5 + 7;
const ll MOD = (ll)1e9;
const int inf = (int)1e9 + 7;
const int B = (int)390;
const ll INF = (ll)1e18 + 7;
pair<int, int> dir[] = {{-1, 0}, {1, 0}, {0, 1}, {0, -1}};
bool bit(int mask, int i) {
return (mask >> i & 1);
}
int sum(int x, int y) {
x += y;
if(x >= MOD) x -= MOD;
return x;
}
int mult(int x, int y) {
return 1ll * x * y % MOD;
}
vector<int> z_function (string s) {
int n = sz(s);
vector<int> z(n);
for (int i = 1, l = 0, r = 0; i < n; ++i) {
if (i <= r)
z[i] = min(r - i + 1, z[i - l]);
while (i + z[i] < n && s[z[i]] == s[i + z[i]])
++z[i];
if (i + z[i] - 1 > r)
l = i, r = i + z[i] - 1;
}
return z;
}
string s;
int cnt[N][N];
bool is[N][N];
void solve() {
cin >> s;
int ans = 0, n = sz(s);
s = '#' + s;
for(int i = 1; i <= n; ++i) {
is[i][i] = 1;
is[i][i - 1] = 1;
}
for(int len = 2; len <= n; ++len) {
for(int i = 1; i <= n; ++i) {
int j = i + len - 1;
is[i][j] = (s[i] == s[j] && is[i + 1][j - 1]);
}
}
for(int i = 1; i <= n; ++i) {
string cur;
for(int j = i; j <= n; ++j) {
cur += s[j];
string t = cur;
t += '#';
t += s;
vector<int> z = z_function(t);
for(auto x : z) {
if(x == j - i + 1) cnt[i][j]++;
}
}
}
for(int i = 1; i <= n; ++i) {
for(int j = i; j <= n; ++j) {
if(!is[i][j]) continue;
ans = max(ans, (j - i + 1) * cnt[i][j]);
}
}
cout << ans << nl;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
//freopen("palindrome.in", "r", stdin);
//freopen("palindrome.out", "w", stdout);
int test = 1;
//cin >> test;
for(int i = 1; i <= test; ++i) {
//cout << "Case " << i << ":\n";
solve();
}
return 0;
}
/*
possible causes of error :
* array bounds
* int overflow
* special case (n == 1?)
* haven't clean something
* wrong N | M | inf | INF | MOD
* try to write brute force to find test
* don't waste time
* don't write bullshit
* solution is easy
*/
