//In the name of God
#include <bits/stdc++.h>
#pragma GCC optimize("O2")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
const ll maxn = 3e5 + 100;
const ll mod = 1e9 + 7;
const ll base = 31;
const ll inf = 1e18;
#define fast_io ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io freopen("input.txt", "r+", stdin);freopen("output.txt", "w+", stdout);
#define pb push_back
#define Mp make_pair
#define F first
#define S second
#define Sz(x) ll((x).size())
#define all(x) (x).begin(), (x).end()
#define lc (id << 1)
#define rc (lc | 1)
ll pw(ll a, ll b){
ll c = 1;
while(b){
if(b & 1) c = c * a % mod;
a = a * a % mod;
b >>= 1;
}
return c;
}
ll n, h[maxn], hp[maxn], p[maxn], pp[maxn];
string s;
map<ll, ll> cnt[maxn];
map<ll, pll> vec[maxn];
ll get1(ll l, ll r){
ll x = (h[r] - h[l - 1] * p[r - l + 1]) % mod;
if(x < 0) x += mod;
return x;
}
ll get2(ll l, ll r){
ll x = hp[r] - hp[l - 1];
if(x < 0) x += mod;
return x * pp[l] % mod;
}
bool ok(ll l, ll r){
if(l < 1 || r > n) return 0;
return (get1(l, r) == get2(l, r));
}
int main(){
p[0] = pp[0] = 1;
for(ll i = 1; i < maxn; i++){
p[i] = p[i - 1] * base % mod;
pp[i] = pw(p[i], mod - 2);
}
cin >> s;
n = Sz(s);
s = ' ' + s;
for(ll i = 1; i <= n; i++){
h[i] = (h[i - 1] * base + ll(s[i] - 'a')) % mod;
hp[i] = (hp[i - 1] + p[i] * ll(s[i] - 'a')) % mod;
}
for(ll i = 1; i <= n; i++){
ll l = 0, r = n;
while(r - l > 1){
ll mid = (l + r) >> 1;
if(ok(i - mid, i + mid)) l = mid;
else r = mid;
}
ll x = get1(i - l, i + l);
cnt[l * 2 + 1][x]++;
vec[l * 2 + 1][x] = Mp(i - l, i + l);
}
for(ll i = 1; i <= n; i++){
ll l = 0, r = n;
while(r - l > 1){
ll mid = (l + r) >> 1;
if(ok(i - mid + 1, i + mid)) l = mid;
else r = mid;
}
if(l == 0) continue;
ll x = get1(i - l + 1, i + l);
cnt[l * 2][x]++;
vec[l * 2][x] = Mp(i - l + 1, i + l);
}
ll ans = 0;
for(ll i = n; i > 0; i--){
for(pll j : cnt[i]){
ans = max(ans, i * j.S);
ll l = vec[i][j.F].F + 1;
ll r = vec[i][j.F].S - 1;
ll x = get1(l, r);
if(i >= 2) cnt[i - 2][x] += j.S;
if(i >= 2) vec[i - 2][x] = Mp(l, r);
}
}
cout << ans;
return 0;
}
