#include <bits/stdc++.h>
using namespace std;
string s;
int main()
{
	cin >> s;
	int l = s.length();
	if((l == 4 || l == 3 ) && s[0] == s[1])
	{
		cout << 2 << endl;
		return 0;
	}
	for(int i = l - 2; i >= 0; i = i - 1)
	{
		if(i % 2 == 0)
			continue;
		int you = i;
		int zuo = (i - 1) / 2;
		bool flag = false;
		while(zuo >= 0 && s[zuo] == s[you])
		{
			zuo --;
			you --;
			if(zuo == 0)
			{
				cout << i + 1 << endl;
				return 0;
			}
		}
	}
	cout << 0 << endl;
	return 0;
}