#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;
ll divide2(ll num, ll den) {
if (num < 0)
{
num += mod2;
}
if (den < 0)
{
den += mod2;
}
ll inv = 1;
ll exp = den;
exp %= mod2;
for (int i = 0; i < 32; i++)
{
if ((mod2-2) & (1<<i))
{
inv *= exp;
inv %= mod2;
}
exp *= exp;
exp %= mod2;
}
ll ans = num * inv;
ans %= mod2;
return ans;
}
ll divide1(ll num, ll den) {
while (num < 0)
{
num += mod1;
}
while (den < 0)
{
den += mod1;
}
ll inv = 1;
ll exp = den;
exp %= mod1;
for (int i = 0; i < 32; i++)
{
if ((mod1-2) & (1<<i))
{
inv *= exp;
inv %= mod1;
}
exp *= exp;
exp %= mod1;
}
ll ans = num * inv;
ans %= mod1;
return ans;
}
int main() {
//cout << divide1(15, 3) << " " << divide2(15, 3) << "\n";
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 << prefSums2[j] << " ";
//cout << prefSums[j] << " " << sufSums[j] << "\n";
}
cout << "\n";
//cout << "\n\n\n";
//cout << prefSums2[8] << " " << pre
for (int i = 1; i < n; i++)
{
for (int j = i; j < n; j++)
{
cout << divide2(prefSums2[j] - prefSums2[i-1], pows2[i]) << " ";
}
cout << "\n";
}
cout << "\n";
for (int i = 0; i < n; i++)
{
for (int j = i; j < n-1; j++)
{
cout << divide2(sufSums2[i] - sufSums2[j+1], pows2[n-1-j]) << " ";
}
cout << sufSums2[i];
cout << "\n";
}*/
ll totMax = 0;
for (int j = 0; j < n-1; j++)
{
if (prefSums[j] == divide1(sufSums[0]-sufSums[j+1], pows[n-1-j]) and prefSums2[j] == divide2(sufSums2[0]-sufSums2[j+1], pows2[n-1-j]))
{
//cout << "Entered\n";
ll curr = 0;
if (m.find(prefSums[j]) != m.end())
{
curr = m.find(prefSums[j])->second;
m.erase(prefSums[j]);
}
curr += j+1;
if (curr > totMax)
{
// cout << "New max of " << curr << " from " << 0 << " to " << j << "\n";
}
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;
if (curr > totMax)
{
//cout << "New max of " << curr << " from " << 0 << " to " << n-1 << "\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 (divide1(prefSums[j]-prefSums[i-1], pows[i]) == divide1(sufSums[i]-sufSums[j+1], pows[n-1-j]) and divide2(prefSums2[j]-prefSums2[i-1], pows2[i]) == divide2(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(divide1(prefSums[j]-prefSums[i-1], pows[i]))->second;
m.erase(divide1(prefSums[j]-prefSums[i-1], pows[i]));
}
curr += j-i+1;
if (curr > totMax)
{
//cout << "New max of " << curr << " from " << i << " to " << j << "\n";
//cout << "Hash value is " << (prefSums[j]-prefSums[i-1])/pows[i] << "\n";
}
totMax = max(totMax, curr);
m.insert({divide1(prefSums[j]-prefSums[i-1], pows[i]), curr});
}
}
if (divide1(prefSums[n-1]-prefSums[i-1], pows[i]) == sufSums[i] and divide2(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;
if (curr > totMax)
{
//cout << "New max of " << curr << " from " << i << " to " << n-1 << "\n";
}
totMax = max(totMax, curr);
m.insert({sufSums[i], curr});
}
}
cout << totMax << "\n";
}
