#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <algorithm>
using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    string s;
    cin >> s;
    int res =0 ;
    int n = (int) s.size();
    for(int sz = n / 4; sz >= 0; sz--) {
        for(int i = 0; i < n; i++) {
            if(i + 4 * sz - 1 < n) {
                
                if(s[i] == s[i + 2 * sz - 1] and s[i] == s[i + 2 * sz] and s[i] == s[i + 4 * sz - 1]) {
                    bool ok = true;
                    int cnt = 1;
                    for(int j = i + 1; j < i + sz; j++) {
                        
                        if(s[j] != s[i + 2 * sz - 1 - cnt] or s[j] != s[j + 2 * sz] or s[j] != s[i + 4 * sz - 1 - cnt]) {
                            ok = false;
                            break;
                        }
                        cnt++;
                    }
                    if(ok) {
                        cout << sz * 4 << endl;
                        return 0;
                    }
                }
            }
        }
    }
    cout << res * 4 << endl;
    return 0;
}