/*
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*/
#include "bits/stdc++.h"
using namespace std;
#define ok1 printf("ok1\n");
#define ok2 printf("ok2\n");
#define M 1000000000000000000LL
#define rep(i,n) for(int i=0;i<n;++i)
#define REP(i,s,n) for(int i=(s);i<(n);++i)
#define repr(i,n) for(int i=n-1;i>=0;--i)
#define REPR(i,s,n) for(int i=(s);i>=(n);--(i))
#define all(a) (a).begin(),(a).end()
#define reall(a) (a).rbegin(),(a).rend()
#define pb push_back
#define pf push_front
#define MIN(a,b) a=min((a),(b))
#define MAX(a,b) a=max((a),(b))
#define SIZE(v) (int)v.size()
#define DOUBLE fixed << setprecision(15)
#define fi first
#define se second
const double pi = acos(-1.0);
typedef vector<int> vi;
typedef vector<string> vs;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef vector<char> vc;
typedef vector<double> vd;
typedef vector<bool> vb;
typedef deque<ll> dll;
typedef pair<ll, ll> P;
typedef vector<P> vP;
const ll mod = 1e9 + 7;
//const ll mod = 998244353;
ll dy[4] = { 1,0,-1,0 };
ll dx[4] = { 0,1,0,-1 };
struct edge {
	int to;
	int cost;
};
bool out_check(ll a, ll b) {
	if (0 <= a && a < b) return true;
	else return false;
}
void Pvll(vll v) {
	cout << "vll------------------------------------------------\n";
	rep(i, v.size()) cout << v[i] << " ";
	cout << endl;
	cout << "------------------------------------------------\n";
}
void Pvvll(vvll v) {
	cout << "vvll------------------------------------------------\n";
	rep(i, v.size()) {
		rep(j, v[i].size()) {
			cout << v[i][j] << " ";
		}
		cout << endl;
	}
	cout << "------------------------------------------------\n";
}

void Ps(string s) {
	cout << "str------------------------------------------------\n";
	rep(i, s.size()) cout << s[i] << " ";
	cout << endl;
	cout << "------------------------------------------------\n";
}

void Pvs(vs s) {
	cout << "vs------------------------------------------------\n";
	rep(i, s.size()) {
		rep(j, s[i].size()) {
			cout << s[i][j] << " ";
		}
		cout << endl;
	}
	cout << "------------------------------------------------\n";
}

void Yes(bool x) {
	if (x) cout << "Yes\n";
	else cout << "No\n";
}

void YES(bool x) {
	if (x) cout << "YES\n";
	else cout << "NO\n";
}

void yes(bool x) {
	if (x) cout << "yes\n";
	else cout << "no\n";
}

void Yay(bool x) {
	if (x) cout << "Yay!\n";
	else cout << ":(\n";
}

ll  n, m, d, r, l, k, h, ans, ret = M;
bool flag = false, flag2 = false, flag3 = false;
string s, t, u;

void INIT() {
	cin.tie(0);
	ios::sync_with_stdio(false);
}
// Returns the longest repeating non-overlapping 
// substring in str 
string longestRepeatedSubstring(string str)
{
	int n = str.length();
	vvll LCSRe(n+1,vll(n+1,0));


	string res; // To store result 
	int res_length = 0; // To store length of result 

						// building table in bottom-up manner 
	int i, index = 0;
	for (i = 1; i <= n; i++)
	{
		for (int j = i + 1; j <= n; j++)
		{
			// (j-i) > LCSRe[i-1][j-1] to remove 
			// overlapping 
			if (str[i - 1] == str[j - 1] &&
				LCSRe[i - 1][j - 1] < (j - i))
			{
				LCSRe[i][j] = LCSRe[i - 1][j - 1] + 1;

				// updating maximum length of the 
				// substring and updating the finishing 
				// index of the suffix 
				if (LCSRe[i][j] > res_length)
				{
					res_length = LCSRe[i][j];
					index = max(i, index);
				}
			}
			else
				LCSRe[i][j] = 0;
		}
	}

	// If we have non-empty result, then insert all 
	// characters from first character to last 
	// character of string 
	if (res_length > 0)
		for (i = index - res_length + 1; i <= index; i++)
			res.push_back(str[i - 1]);

	return res;
}
int main() {
	INIT();
	string s;
	cin >> n >> s;
	cout << longestRepeatedSubstring(s).size() << endl;
	return 0;
}

Measured memory_bytes: 195840