#include <iostream>
#include <cstdio>

using namespace std;

string s;
int n, ans;

int main() {
    cin >> s;
    n = s.size();
    s = ' ' + s;
    ans = 0;
    for (int i = 1; i <= n; ++i) {
        for (int j = i; j <= n; ++j) {
            int cnt = 0;
            for (int k = i; k <= (i + j) / 2; ++k) {
                if (s[k] == s[i + j - k]) cnt += (k == i + j - k ? 1 : 2);
            }
            ans = max(ans, cnt);
        }
    }

    printf("%d\n", ans);

    return 0;
}