#include <bits/stdc++.h>
#define pii pair<ll, ll>
typedef long long ll;
using namespace std;
const ll MAX = 600006, MOD1 = 998244353, MOD2 = 846545669;
char C[MAX];
int P[MAX];
ll D[2][MAX], IP[2][MAX], ans;
map<ll, ll> cnt, Z;
map<ll, vector<ll>> G;
ll Pow(ll N, ll K, const ll MOD) {
ll ret = 1;
while (K) {
if (K & 1) ret = ret * N % MOD;
N = N * N % MOD;
K >>= 1LL;
}
return ret;
}
ll Hash(int L, int R) {
if (L > R) return -1;
R++;
ll a = (D[0][R] - D[0][L] + MOD1) * IP[0][L] % MOD1;
ll b = (D[1][R] - D[1][L] + MOD2) * IP[1][L] % MOD2;
return (a << 31LL) + b;
}
ll DFS(ll cur) {
ll n = cnt[cur];
for (ll next : G[cur]) n += DFS(next);
ans = max(ans, n * Z[cur]);
return n;
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
string A, B;
cin >> A;
for (char c : A) {
B.push_back(c);
B.push_back('_');
}
B.pop_back();
int N = A.size(), M = B.size();
D[0][0] = D[1][0] = IP[0][0] = IP[1][0] = 1;
ll p1 = 1, p2 = 1, ip1 = Pow(313, MOD1 - 2, MOD1), ip2 = Pow(479, MOD2 - 2, MOD2);
for (int i = 0; i < N; ++i) {
C[i] = A[i];
D[0][i + 1] = (D[0][i] + C[i] * p1) % MOD1;
D[1][i + 1] = (D[1][i] + C[i] * p2) % MOD2;
IP[0][i + 1] = IP[0][i] * ip1 % MOD1;
IP[1][i + 1] = IP[1][i] * ip2 % MOD2;
p1 = p1 * 313 % MOD1;
p2 = p2 * 479 % MOD2;
}
int R = -1, K = -1;
for (int i = 0; i < M; ++i) {
if (i <= R) P[i] = min(R - i, P[2 * K - i]);
while (i - P[i] - 1 >= 0 && i + P[i] + 1 < M && B[i - P[i] - 1] == B[i + P[i] + 1]) P[i]++;
if (R < i + P[i]) R = i + P[i], K = i;
}
for (int i = 0; i < M; ++i) {
int l = i - P[i], r = i + P[i];
if (l & 1) l++;
if (r & 1) r--;
if (l > r) continue;
l >>= 1, r >>= 1;
ll pv = 0, cur = Hash(l, r), cut = Z.find(cur) != Z.end();
cnt[cur]++;
Z[cur] = r - l + 1;
do {
if (pv) G[cur].push_back(pv);
if (cut) break;
pv = cur;
l++; r--;
if (l <= r) {
cur = Hash(l, r);
if (Z.find(cur) != Z.end()) cut = 1;
else Z[cur] = r - l + 1;
}
} while (l <= r);
if (l > r) G[0].push_back(cur);
}
DFS(0);
cout << ans;
return 0;
}
