#include <bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
#define pii pair<int,int>
#define vi vector<int>
#define fi first
#define se second
#define pb push_back
#define ALL(x) x.begin(),x.end()
#define sz(x) int(x.size())
#define ll long long
using namespace std;
const int N = 5e3 + 5;
int n,ok[N][N],dp[N];
char s[N];
int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin >> (s + 1);
    while(s[n + 1])n++;
    dp[0] = n;
    rep(i,1,n)ok[i][i] = 1;
    rep(len,2,n)rep(i,1,n){
        int j = i + len - 1;
        if(len == 2 && s[i] == s[j])ok[i][j] = 1;
        if(len > 2 && s[i] == s[j])ok[i][j] = ok[i + 1][j - 1];
    }
    rep(i,1,n)rep(j,1,i){
        if(ok[j][i])dp[i] = max(dp[i],min(dp[j - 1],i - j + 1));
    }
    cout << dp[n] << endl;
    return 0;
}