#include <bits/stdc++.h>
using namespace std;

int main(){
	string s;
	cin >> s;
	int ans = 1,check = 0;
	if(s.size() == 2) ans = 1;
	else{
		for(int i = 0; i < s.size()-ans; i++){
			for(int j = i + 1; j < s.size(); j++){
				if(s[i] == s[j]){
					//					cout << s[i] << " " << s[j] << endl;
					int x = j;
					for(int k = i+1; k <= (i+j)/2; k++){
						x--;
						//						cout << x << endl;
						//						cout << k << " " << x << endl;
						//						cout << s[k] << " " << s[x] << endl;
						if(s[k] == s[x]) check = 1;
						else{
							check = 0;
							break;
						}
					}
					if(check){
						ans = max(ans,j-i+1);
						check = 0;
					}
				}
			}
		}
	}
	cout << ans << endl;
	return 0;
}