#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=2167167167167167167;
const int INF=2100000000;
const int mod=998244353;
#define rep(i,a,b) for (int i=a;i<b;i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}
template<class T> T min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T sum(vector<T> &a){assert(!a.empty());T ans=a[0]-a[0];for(auto &x:a) ans+=x;return ans;}


namespace po167{
//LCP vec[0,n) and vec[i,n)
//for all i 
//O(vec.size())
template<class T>
std::vector<int> Z_algo(std::vector<T> &vec){
	int n=vec.size();
	int ind=1,j=0,k;
	std::vector<int> ans(n,0);
	ans[0]=n;
	while(ind<n){
		while(ind+j<n&&vec[j]==vec[ind+j]) j++;
		ans[ind]=j;
		if(j==0){
			ind++;
			continue;
		}
		k=1;
		while(k+ind<n&&ans[k]+k<j){
			ans[k+ind]=ans[k];
			k++;
		}
		j-=k;
		ind+=k;
	}
	return ans;
}
std::vector<int> Z_algo(std::string &vec){
	int n=vec.size();
	int ind=1,j=0,k;
	std::vector<int> ans(n,0);
	ans[0]=n;
	while(ind<n){
		while(ind+j<n&&vec[j]==vec[ind+j]) j++;
		ans[ind]=j;
		if(j==0){
			ind++;
			continue;
		}
		k=1;
		while(k+ind<n&&ans[k]+k<j){
			ans[k+ind]=ans[k];
			k++;
		}
		j-=k;
		ind+=k;
	}
	return ans;
}
}
using po167::Z_algo;

void solve();
// oddloop
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	//cin>>t;
	rep(i,0,t) solve();
}

void solve(){
	string S;
	cin>>S;
	int N=S.size();
	vector<int> dp(N+1,-1);
	dp[0]=N;
	rep(i,0,N){
		string T=S.substr(i,N-i);
		string U=T;
		reverse(all(T));
		U+="#";
		U+=T;
		auto Z=Z_algo(U);
		rep(k,0,N-i){
			if(k+1==Z[2*(N-i)-k]) chmax(dp[i+k+1],min(dp[i],k+1));
		}
		//vec_out(dp);
	}
	cout<<dp[N]<<"\n";
}