#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)3e5 + 7;
const int M = (int)2e6 + 5e5 + 7;
const ll MOD = (ll)998244353;
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 sub(int x, int y) {
x -= y;
if(x < 0) x += MOD;
return x;
}
int mult(int x, int y) {
return 1ll * x * y % MOD;
}
string s;
int n, p[N], h[N];
int get(int l, int r) {
return mult(sub(h[r], h[l - 1]), p[n - r + 1]);
}
void solve() {
cin >> s;
n = sz(s);
s = '#' + s;
for(int i = 1; i <= n; ++i) {
h[i] = sum(h[i - 1], mult(s[i] - 'a' + 1, p[i]));
}
unordered_map<int, int> cnt[n + 1];
for(int i = 1; i <= n; ++i) {
int l = i + 1, r = i - 1;
while(s[l - 1] == s[r + 1]) {
l--;
r++;
if(l < 1 || r > n) break;
cnt[r - l + 1][get(l, r)]++;
}
l = i + 1, r = i;
while(s[l - 1] == s[r + 1]) {
l--;
r++;
if(l < 1 || r > n) break;
cnt[r - l + 1][get(l, r)]++;
}
}
int ans = 0;
for(int i = 1; i <= n; ++i) {
for(auto [x, y] : cnt[i]) {
ans = max(ans, y * i);
}
}
cout << ans << nl;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
p[0] = 1;
for(int i = 1; i <= 1e5; ++i) {
p[i] = mult(p[i - 1], 31);
}
//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
*/
