#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 trie {
map<int,int> nex[mxN];
int pa[mxN][lgN], v[mxN], cnt;
trie() {
cnt = 1;
v[0] = 0;
FOR(k,0,lgN-1) pa[0][k] = -1;
}
int make(int fa) {
int u = cnt++;
v[u] = 0;
pa[u][0] = fa;
FOR(k,1,lgN-1) pa[u][k] = (pa[u][k-1] == -1 ? -1 : pa[pa[u][k-1]][k-1]);
return u;
}
int nthPa(int u, int n) {
RFOR(k,lgN-1,0) if (n&(1<<k)) {
if (u == -1) break;
else u = pa[u][k];
}
return u;
}
int get(int u, char c) {
if (!nex[u].count(c-'a')) {
nex[u][c-'a'] = make(u);
}
return nex[u][c-'a'];
}
ll ans(int u, int d) {
//TRACE(d _ v);
ll r = 0;
for (auto& c : nex[u]) {
r = max(r, ans(c.second,d+1));
v[u] += v[c.second];
}
r = max(r, (ll)d*v[u]);
return r;
}
} root;
int cur[mxN];
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);
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] = root.nthPa(cur[_i],P[_i]-P[i]);
} else {
cur[i] = root.get(0,T[i]);
}
while (T[i+P[i]+1] == T[i-P[i]-1]) {
cur[i] = root.get(cur[i],T[i+P[i]+1]);
++P[i];
}
++root.v[cur[i]];
if (i+P[i] > r) m = i, r = i+P[i];
}
cout << root.ans(0,-1) << '\n';
//cout << T << '\n';
//FOR(i,0,N-1) cout << P[i] << ' ';
//cout << endl;
//root->dbg("",-1);
}
