#include <bits/stdc++.h>
using namespace std;
#define ll long long
inline void out(ll x) {
ll rev=x;
int cnt=0;
while(rev%10==0) {
rev/=10;
++cnt;
}
rev=0;
while(x) {
rev=rev*10+x%10;
x/=10;
}
while(rev) {
putchar_unlocked(rev%10+'0');
rev/=10;
}
while(cnt--)
putchar_unlocked('0');
}
const int mxN=4e5, mxlgN=18;
int n, m=123, sa1[mxN], sa2[mxN], cl1[mxN*2], cl2[mxN], cnt[mxN], lcp[mxlgN+1][mxN], p[mxN*2+3];
char s[mxN+1], s2[mxN*2+3];
inline int lcpq(int l, int r) {
int k=31-__builtin_clz(r-l+1);
return min(lcp[k][l], lcp[k][r-(1<<k)+1]);
}
int main() {
while(1) {
char c=getchar_unlocked();
if(c==' '||c=='\n'||c=='\r')
break;
s[n++]=c;
}
for(int i=0; i<n; ++i)
cl1[i]=s[i];
for(int l=1; l<=n; l*=2) {
memset(cnt, 0, 4*m);
for(int i=0; i<n; ++i)
++cnt[cl1[i+l]];
for(int i=1; i<m; ++i)
cnt[i]+=cnt[i-1];
for(int i=n-1; i>=0; --i)
sa2[--cnt[cl1[i+l]]]=i;
memset(cnt, 0, 4*m);
for(int i=0; i<n; ++i)
++cnt[cl1[i]];
for(int i=1; i<m; ++i)
cnt[i]+=cnt[i-1];
for(int i=n-1; i>=0; --i)
sa1[--cnt[cl1[sa2[i]]]]=sa2[i];
m=0;
for(int i=0; i<n; ++i) {
if(!i||cl1[sa1[i]]!=cl1[sa1[i-1]]||cl1[sa1[i]+l]!=cl1[sa1[i-1]+l])
++m;
cl2[sa1[i]]=m;
}
++m;
memcpy(cl1, cl2, 4*n);
}
s[n]='$';
for(int i=0, k=0; i<n; ++i, k-=k>0) {
if(cl1[i]>=n)
continue;
for(int j=sa1[cl1[i]]; s[i+k]==s[j+k]; ++k);
lcp[0][cl1[i]]=k;
}
// for(int i=1; i<n; ++i)
// cout << lcp[0][i] << " ";
// cout << endl;
for(int k=1; k<=mxlgN; ++k)
for(int i=0; i<=n-(1<<k); ++i)
lcp[k][i]=min(lcp[k-1][i], lcp[k-1][i+(1<<(k-1))]);
int c=-1, r=-1;
s2[0]='!', s2[1]='#', s2[2*n+2]='@';
for(int i=0; i<n; ++i) {
s2[2*i+2]=s[i];
s2[2*i+3]='#';
}
ll ans=0;
for(int i=1; i<=2*n+1; ++i) {
if(r>=i)
p[i]=min(r-i, p[2*c-i]);
// cout << i << " " << p[i] << endl;
while(s2[i+p[i]]==s2[i-p[i]]) {
if((i-p[i])%2==0) {
int j=(i-p[i])/2-1, l=p[i]+1, tl=1, lb, rb;
assert(j<n);
// cout << j << " " << l << endl;
lb=1, rb=cl1[j]-1;
assert(cl1[j]<=n);
while(lb<=rb) {
int mb=(lb+rb)/2;
if(lcpq(mb, cl1[j]-1)>=l)
rb=mb-1;
else
lb=mb+1;
}
tl+=cl1[j]-lb;
lb=cl1[j], rb=n-1;
while(lb<=rb) {
int mb=(lb+rb)/2;
if(lcpq(cl1[j], mb)>=l)
lb=mb+1;
else
rb=mb-1;
}
tl+=rb-cl1[j]+1;
ans=max((long long)tl*l, ans);
}
++p[i];
}
--p[i];
if(i+p[i]>r) {
c=i;
r=i+p[i];
}
// cout << i << " " << p[i] << endl;
}
out(ans);
}
