#include <bits/stdc++.h>
using namespace std;
#define TRACE(x) cerr << #x << " :: " << x << endl
#define _ << " " <<
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(),(x).end()
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define RFOR(i,a,b) for (int i=(a);i>=(b);--i)
using ll=long long;
const int mxN = 600010;
const int lgN = 20;
struct node {
static const int A = 26+3;
node* pa[lgN];
node* child[A];
int v;
node(node* fa): v(0) {
pa[0] = fa;
FOR(k,1,lgN-1) pa[k] = (pa[k-1] != NULL ? pa[k-1]->pa[k-1] : NULL);
FOR(i,0,lgN-1) pa[i] = NULL;
FOR(i,0,A-1) child[i] = NULL;
}
node* nthPa(int n) {
node* r = this;
RFOR(k,lgN-1,0) if (n&(1<<k)) {
if (r != NULL) r = r->pa[k];
}
return r;
}
node* get(char c) {
if (child[c-'a'] == NULL) {
child[c-'a'] = new node(this);
}
return child[c-'a'];
}
void add(int x) { v += x; }
ll ans(int d) {
//TRACE(d _ v);
ll r = 0;
FOR(i,0,A-1) if (child[i] != NULL) {
r = max(r, child[i]->ans(d+1));
v += child[i]->v;
}
r = max(r, (ll)d*v);
return r;
}
void dbg(string S, int d) {
TRACE(S _ "::" _ d _ v);
FOR(i,0,A-1) if (child[i] != NULL) {
child[i]->dbg(S + char('a'+i), d+1);
}
}
} *cur[mxN], *root;
string S, T;
int N, P[mxN];
string preprocess(string S) {
string T = "{";
for (auto& c : S) {
T += "|";
T += c;
}
T += "|}";
return T;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cin >> S;
T = preprocess(S);
N = SZ(T);
root = new node(NULL);
int m = 0, r = 0;
fill_n(P,N,0);
FOR(i,1,N-2){
int _i = m - (i-m);
if (r > i) {
P[i] = min(P[_i], r-i);
cur[i] = cur[_i]->nthPa(P[_i]-P[i]);
} else {
cur[i] = root->get(T[i]);
}
while (T[i+P[i]+1] == T[i-P[i]-1]) {
cur[i] = cur[i]->get(T[i+P[i]+1]);
++P[i];
}
cur[i]->add(1);
if (i+P[i] > r) m = i, r = i+P[i];
}
cout << root->ans(-1) << '\n';
//cout << T << '\n';
//FOR(i,0,N-1) cout << P[i] << ' ';
//cout << endl;
//root->dbg("",-1);
}
