#include <bits/stdc++.h>
using namespace std;
#define sz size()
#define ll long long
int main () {
// freopen ("input.txt", "r", stdin);
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
string s;
cin >> s;
int n = (int)s.sz;
s = " " + s;
string hh = s;
int jogap = 0;
for (int oo = 1; oo <= n; ++oo) {
for (char o = 'a'; o <= 'z'; ++o) {
s[oo] = o;
string k;
// if (oo == 2 and o == 'c') {
// if (s != "bcccd") {
// continue;
// return cout << s, 0;
// }
// if (s)
int jog = 0;
for (int i = 1; i <= n; ++i) {
string k;
for (int j = i; j <= n; ++j) {
k += s[j];
// cout << k << ' ';
int tr = 0;
for (int l = 0; l < (int)k.sz / 2; ++l) {
tr |= (k[l] != k[(int)k.sz - l - 1]);
}
if (!tr) {
jog++;
}
}
}
jogap = max (jogap, jog);
}
s = hh;
}
cout << jogap;
}
