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

int main(){
    string s; cin >> s;
    const int n = s.size();
    vector<vector<bool>> ispalindrome(n+1, vector<bool>(n+1, false));
    for(int i = 0; i < n; i++){
        for(int j = 0; 0 <= i-j && i+j < n; j++){
            if(s[i-j] != s[i+j]) break;
            ispalindrome[i-j][i+j+1] = true;
        }
        if(i+1 < n && s[i] == s[i+1]){
            for(int j = 0; 0 <= i-j && i+j+1 < n; j++){
                if(s[i-j] != s[i+j+1]) break;
                ispalindrome[i-j][i+j+2] = true;
            }
        }
    }

    vector<int> dp(n+1, -(1 << 30));
    dp[0] = 1 << 30;
    for(int i = 0; i < n; i++){
        for(int j = 0; j <= i; j++){
            if(ispalindrome[j][i+1]){
                dp[i+1] = max(dp[i+1], min(dp[j], i+1-j));
            }
        }
        // cerr << dp[i+1] << " ";
    }
    cout << dp[n] << endl;
    return 0;
}