#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <complex>
#include <chrono>
#include <random>
#include <functional>
using namespace std;
int pal(string s) {
string t = s;
reverse(t.begin(), t.end());
return s == t;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
string s;
cin >> s;
int n = (int)s.size();
map<string, int> cnt;
int ans = 0;
for (int i = 0; i < n; i++) {
for (int j = i; j < n; j++) {
string ts = s.substr(i, j - i + 1);
if (pal(ts)) {
cnt[ts]++;
ans = max(ans, cnt[ts] * (j - i + 1));
}
}
}
cout << ans << endl;
}
