#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n;
char str[400002];
ll ans;
void input();
void init();
void dnc();
int main(){
input();
init();
dnc();
printf("%lld", ans);
}
void input(){
// n=300000;
// for(int i=1; i<=n; i++) str[i] = 'a';
scanf("%s", str+1);
n = strlen(str+1);
if(n==1){
printf("1");
exit(0);
}
}
int sa[400005], pos[400005], lcp[400005];
int d;
bool cmp(int i, int j){
if(pos[i] != pos[j]) return pos[i] < pos[j];
i += d;
j += d;
return (i <= n && j <= n) ? (pos[i] < pos[j]) : (i > j);
}
int temp[600005] = {0};
void constructSA(){
for(int i=1; i<=n; i++){
sa[i] = i;
pos[i] = str[i];
}
for(d=1; ; d*=2){
sort(sa+1, sa+n+1, cmp);
memset(temp, 0, sizeof(temp));
for(int i=0; i<=n; i++) temp[i] = 1;
for(int i=1; i<n; i++)
temp[i+1] = temp[i] + cmp(sa[i], sa[i+1]);
for(int i=1; i<=n; i++)
pos[sa[i]] = temp[i];
if(temp[n] == n) break;
}
}
void constructLCP(){
for(int i=1, k=0; i<=n; i++, k=max(k-1, 0)){
if(pos[i] == n) continue;
for(int j=sa[pos[i]+1]; str[i+k]==str[j+k]; k++);
lcp[pos[i]] = k;
}
}
int pal[400005];
void manacher(){
char arr[700005] = {0};
for(int i=1; i<=n; i++) arr[i*2-1] = arr[i*2+1] = '#', arr[i*2] = str[i];
arr[0] = 'S', arr[n*2+2] = 'T';
int maxVal = -1, maxIdx = -1;
for(int i=1; i<=n*2+1; i++){
if(maxVal < i) pal[i] = 0;
else pal[i] = min(pal[maxIdx*2-i], maxVal-i);
while(arr[i-pal[i]-1] == arr[i+pal[i]+1]) pal[i]++;
if(i + pal[i] > maxVal) maxVal = i+pal[i], maxIdx = i;
}
/// 한 번 나오는 케이스 처리
for(int i=1; i<=n*2+1; i++){
if(i%2==1) ans = max(ans, ll(pal[i]+1)/2*2);
else ans = max(ans, ll(pal[i])/2*2+1);
}
}
pair<int, int> tree[1400002];
void init(int i, int l, int r){
if(l==r){
tree[i] = make_pair(lcp[l], l);
return;
}
int m = (l+r)>>1;
init(i*2, l, m);
init(i*2+1, m+1, r);
tree[i] = min(tree[i*2], tree[i*2+1]);
}
pair<int, int> query(int i, int l, int r, int s, int e){
if(r<s || e<l) return make_pair(1000000000, -1);
if(s<=l && r<=e) return tree[i];
int m = (l+r)>>1;
return min(query(i*2, l, m, s, e), query(i*2+1, m+1, r, s, e));
}
int tree2[2800002];
void init2(int i, int l, int r){
if(l==r){
tree2[i] = l-pal[l];
return;
}
int m = (l+r)>>1;
init2(i*2, l, m);
init2(i*2+1, m+1, r);
tree2[i] = min(tree2[i*2], tree2[i*2+1]);
}
int query2(int i, int l, int r, int s, int e, int v){
if(r<s || e<l || tree2[i] > v) return 0;
if(l==r) return l;
int m = (l+r)>>1;
int tmp = query2(i*2+1, m+1, r, s, e, v);
if(tmp) return tmp;
return query2(i*2, l, m, s, e, v);
}
void init(){
constructSA();
constructLCP();
manacher();
init(1, 1, n-1);
init2(1, 1, n+n+1);
#ifdef TEST
// for(int i=1; i<=n; i++) printf("%d ", sa[i]); puts("");
// for(int i=1; i<=n; i++) printf("%d ", lcp[i]); puts("");
// for(int i=1; i<=n*2+1; i++) printf("%d ", pal[i]); puts("");
for(int i=1; i<=n; i++) assert(sa[i] == n+1-i);
for(int i=1; i<n; i++) assert(lcp[i] == i);
#endif // TEST
}
void dnc(int l, int r){
if(l>r) return;
pair<int, int> p = query(1, 1, n-1, l, r);
dnc(l, p.second-1);
dnc(p.second+1, r);
/// 현재 상황 처리하기
int s = sa[l];
int e = s + p.first - 1;
int tmp = query2(1, 1, n+n+1, s+s, s+e, s+s);
if(!tmp) return;
ans = max(ans, ll(tmp-(s+s)+1) * ll(r-l+2));
}
void dnc(){
return dnc(1, n-1);
}
