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

typedef modint998244353 mint;
typedef long long ll;

// isprime
bool isprime(ll n){
	if (n == 1) return false;
	for (ll i = 2; i * i <= n; i++){
		if (n % i == 0) return false;
	}
	return true;
}


// importrandom
// don't forget randomjumon
// and also isprime
ll RandomMod(ll l, ll r){
	ll ret = l + rand() % (r - l);
	while (!isprime(ret)) ret = l + rand() % (r - l);
	return ret;
}

ll randrange(ll l, ll r){
	return l + rand() % (r - l);
}
// -----


int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	srand((unsigned)time(NULL));
	
	// Rolling Hash
	// don't forget randomjumon and importrandom
	typedef dynamic_modint<0> mint1;
	typedef dynamic_modint<1> mint2;
	
	int mod1 = RandomMod(7e8, 1e9);
	int mod2 = RandomMod(7e8, 1e9);
	
	mint1::set_mod(mod1);
	mint2::set_mod(mod2);
	
	mint1 b1 = randrange(100, 200);
	mint2 b2 = randrange(100, 200);
	
	int MAX_m = 10000;
	vector<mint1> b1l(MAX_m+1);
	b1l[0] = 1;
	for (int i=0; i<MAX_m; i++){
		b1l[i+1] = b1l[i] * b1;
	}
	
	vector<mint2> b2l(MAX_m+1);
	b2l[0] = 1;
	for (int i=0; i<MAX_m; i++){
		b2l[i+1] = b2l[i] * b2;
	}
	// -----

	int INF = 1e9;

	string s; cin >> s;
	int n = s.size();
	vector<vector<int>> dp(n+1, vector<int>(n+1, -INF));
	dp[0][0] = INF;
	mint1 r1 = 0;
	mint2 r2 = 0;
	vector<mint1> s1(n+1);
	vector<mint2> s2(n+1);
	vector<mint1> t1(n+1);
	vector<mint2> t2(n+1);

	for (int i=0; i<n; i++){
		r1 = r1 * b1 + s[i] - 'a' + 1;
		r2 = r2 * b2 + s[i] - 'a' + 1;
		s1[i+1] = r1;
		s2[i+1] = r2;
	}

	r1 = 0;
	r2 = 0;
	for (int i=n-1; i>=0; i--){
		r1 = r1 * b1 + s[i] - 'a' + 1;
		r2 = r2 * b2 + s[i] - 'a' + 1;
		t1[i] = r1;
		t2[i] = r2;
	}

	mint1 x1, y1;
	mint2 x2, y2;
	for (int i=0; i<n; i++){
		for (int j=0; j<=i; j++){
			x1 = s1[i+1] - s1[j] * b1l[i-j+1];
			x2 = s2[i+1] - s2[j] * b2l[i-j+1];
			y1 = t1[j] - t1[i+1] * b1l[i-j+1];
			y2 = t2[j] - t2[i+1] * b2l[i-j+1];
			if (x1 == y1 && x2 == y2){
				dp[i+1][i+1] = max(dp[i+1][i+1], min(dp[i][j], i-j+1));
			}
		}
		for (int j=0; j<=i; j++){
			dp[i+1][j] = max(dp[i+1][j], dp[i][j]);
		}
	}

	cout << dp[n][n] << endl;
}