#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll mod1 = 1000000007;
ll mod2 = 1000000009;
string s;
ll n;
ll prefSums[20000], sufSums[20000];
ll prefSums2[20000], sufSums2[20000];
ll pows[20000], pows2[20000];
unordered_map<ll, ll> m;
int main() {
cin >> s;
ll thisPow = 1;
ll thisPow2 = 1;
n = s.length();
for (int i = 0; i < n; i++)
{
pows[i]= thisPow;
thisPow *= 11;
thisPow %= mod1;
pows2[i]= thisPow2;
thisPow2 *= 13;
thisPow2 %= mod2;
}
prefSums[0] = s[0] - 'a' + 1;
prefSums2[0] = s[0] - 'a' + 1;
for (int i = 1; i < n; i++)
{
prefSums[i] = prefSums[i-1] + (s[i] - 'a' + 1) * pows[i];
prefSums[i] %= mod1;
prefSums2[i] = prefSums2[i-1] + (s[i] - 'a' + 1) * pows2[i];
prefSums2[i] %= mod2;
}
sufSums[n-1] = s[n-1] - 'a' + 1;
sufSums2[n-1] = s[n-1] - 'a' + 1;
for (int i = n-2; i >= 0; i--)
{
sufSums[i] = sufSums[i+1] + (s[i] - 'a' + 1) * pows[n-1-i];
sufSums[i] %= mod1;
sufSums2[i] = sufSums2[i+1] + (s[i] - 'a' + 1) * pows2[n-1-i];
sufSums2[i] %= mod2;
}
/*for (int j = 0; j < n; j++)
{
cout << prefSums[j] << " ";
//cout << prefSums[j] << " " << sufSums[j] << "\n";
}
cout << "\n";
for (int i = 1; i < n; i++)
{
for (int j = i; j < n; j++)
{
cout << (prefSums[j] - prefSums[i-1]) / pows[i] << " ";
}
cout << "\n";
}
cout << "\n";
for (int i = 0; i < n; i++)
{
for (int j = i; j < n-1; j++)
{
cout << (sufSums[i] - sufSums[j+1]) / pows[n-1-j] << " ";
}
cout << sufSums[i];
cout << "\n";
}*/
ll totMax = 0;
for (int j = 0; j < n-1; j++)
{
if (prefSums[j] == (sufSums[0]-sufSums[j+1])/pows[n-1-j] and prefSums2[j] == (sufSums2[0]-sufSums2[j+1])/pows2[n-1-j])
{
ll curr = 0;
if (m.find(prefSums[j]) != m.end())
{
curr = m.find(prefSums[j])->second;
m.erase(prefSums[j]);
}
curr += j+1;
totMax = max(totMax, curr);
m.insert({prefSums[j], curr});
}
}
if (prefSums[n-1] == sufSums[0] and prefSums2[n-1] == sufSums2[0])
{
ll curr = 0;
if (m.find(prefSums[n-1]) != m.end())
{
curr = m.find(prefSums[n-1])->second;
m.erase(prefSums[n-1]);
}
curr += n;
totMax = max(totMax, curr);
m.insert({prefSums[n-1], curr});
}
for (int i = 1; i < n; i++)
{
for (int j = i; j < n-1; j++)
{
if ((prefSums[j]-prefSums[i-1])/pows[i] == (sufSums[i]-sufSums[j+1])/pows[n-1-j] and (prefSums2[j]-prefSums2[i-1])/pows2[i] == (sufSums2[i]-sufSums2[j+1])/pows2[n-1-j])
{
ll curr = 0;
if (m.find((prefSums[j]-prefSums[i-1])/pows[i]) != m.end())
{
curr = m.find((prefSums[j]-prefSums[i-1])/pows[i])->second;
m.erase((prefSums[j]-prefSums[i-1])/pows[i]);
}
curr += j-i+1;
totMax = max(totMax, curr);
m.insert({(prefSums[j]-prefSums[i-1])/pows[i], curr});
}
}
if ((prefSums[n-1]-prefSums[i-1])/pows[i] == sufSums[i] and (prefSums2[n-1]-prefSums2[i-1])/pows2[i] == sufSums2[i])
{
ll curr = 0;
if (m.find(sufSums[i]) != m.end())
{
curr = m.find(sufSums[i])->second;
m.erase(sufSums[i]);
}
curr += n-i;
totMax = max(totMax, curr);
m.insert({sufSums[i], curr});
}
}
cout << totMax << "\n";
}
