#define DEBUG 0
#include <bits/stdc++.h>
using namespace std;
#if DEBUG
// basic debugging macros
int __i__,__j__;
#define printLine(l) for(__i__=0;__i__<l;__i__++){cout<<"-";}cout<<endl
#define printLine2(l,c) for(__i__=0;__i__<l;__i__++){cout<<c;}cout<<endl
#define printVar(n) cout<<#n<<": "<<n<<endl
#define printArr(a,l) cout<<#a<<": ";for(__i__=0;__i__<l;__i__++){cout<<a[__i__]<<" ";}cout<<endl
#define print2dArr(a,r,c) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<a[__i__][__j__]<<" ";}cout<<endl;}
#define print2dArr2(a,r,c,l) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<setw(l)<<setfill(' ')<<a[__i__][__j__]<<" ";}cout<<endl;}
// advanced debugging class
// debug 1,2,'A',"test";
class _Debug {
public:
template<typename T>
_Debug& operator,(T val) {
cout << val << endl;
return *this;
}
};
#define debug _Debug(),
#else
#define printLine(l)
#define printLine2(l,c)
#define printVar(n)
#define printArr(a,l)
#define print2dArr(a,r,c)
#define print2dArr2(a,r,c,l)
#define debug
#endif
// define
#define MAX_VAL 999999999
#define MAX_VAL_2 999999999999999999LL
#define EPS 1e-6
#define mp make_pair
#define pb push_back
// typedef
typedef unsigned int UI;
typedef long long int LLI;
typedef unsigned long long int ULLI;
typedef unsigned short int US;
typedef pair<int,int> pii;
typedef pair<LLI,LLI> plli;
typedef vector<int> vi;
typedef vector<LLI> vlli;
typedef vector<pii> vpii;
typedef vector<plli> vplli;
// ---------- END OF TEMPLATE ----------
char s[300001];
struct node {
int l,s;
int ins[26];
int n;
};
node nodes[300003];
int num = 2;
vi adjList[300003];
int occ[300003];
LLI ans = 0;
int doDFS(int u) {
int i;
occ[u] = nodes[u].n;
for (i = 0; i < adjList[u].size(); i++) occ[u] += doDFS(adjList[u][i]);
ans = max(ans,(LLI) occ[u]*nodes[u].l);
return occ[u];
}
int main() {
scanf("%s",s);
int l = strlen(s);
int i;
nodes[1].l = -1,nodes[1].s = 1,nodes[1].n = 0;
nodes[2].l = 0,nodes[2].s = 1,nodes[2].n = 0;
int suff = 2;
for (i = 0; i < l; i++) {
int c = suff;
while (1) {
if (((i-nodes[c].l-1) >= 0) && (s[i-nodes[c].l-1] == s[i])) break;
else c = nodes[c].s;
}
if (nodes[c].ins[s[i]-'a'] > 0) {
nodes[nodes[c].ins[s[i]-'a']].n++;
suff = nodes[c].ins[s[i]-'a'];
}
else {
nodes[c].ins[s[i]-'a'] = suff = ++num;
nodes[num].l = nodes[c].l+2,nodes[num].n = 1;
c = nodes[c].s;
if (nodes[num].l == 1) nodes[num].s = 2;
else {
while (1) {
if (((i-nodes[c].l-1) >= 0) && (s[i-nodes[c].l-1] == s[i])) break;
else c = nodes[c].s;
}
nodes[num].s = nodes[c].ins[s[i]-'a'];
}
}
}
for (i = 2; i <= num; i++) adjList[nodes[i].s].pb(i);
doDFS(1);
printf("%lld\n",ans);
return 0;
}
