#include<bits/stdc++.h>

#define hell                         1000000007
#define lcm(a,b)                     (a*b)/__gcd(a,b)
#define ll                           long long
#define vll                          vector<ll>
#define vi                           vector<int>
#define pll                          vector< pair<ll,ll> >
#define pb                           push_back
#define mp                           make_pair
#define all(v)                       v.begin(),v.end()
#define lbnd                         lower_bound
#define ubnd                         upper_bound
#define bs                           binary_search
#define F                            first
#define S                            second
#define rep(i,a,b)                   for(i=a;i<b;i++)
#define parr(a,n)                    for(ll it=0;it<n;it++) cout<<a[it]<<" ";cout<<endl;
#define pcont(a)                     for(auto it:a) cout<<it<<" ";cout<<endl;
#define ret(x)                       return cout<<x,0;
#define endl                           '\n'

/*constants*/
#define MAXN                         100005
#define PI                           3.14159265358979323846

/*debug*/
#define TRACE
#ifdef TRACE
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
    template <typename Arg1>void __f(const char* name, Arg1&& arg1){ std::cout << name << " : " << arg1 << '\n';}
    template <typename Arg1, typename... Args>void __f(const char* names, Arg1&& arg1, Args&&... args){const char* comma = strchr(names + 1, ','); std::cout.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...);}
#else
#define trace(...)
#endif

using namespace std;

string longestRepeatedSubstring(string str) 
{ 
    int n = str.length(); 
    int LCSRe[n+1][n+1]; 
  
    // Setting all to 0 
    memset(LCSRe, 0, sizeof(LCSRe)); 
  
    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()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    
    ll i,j,n,m,k,cnt=0,ans=0,t=1;
    cin>>n;
    string s;
    cin>>s;
    ret(longestRepeatedSubstring(s).length());
    
    return 0;
}

Measured memory_bytes: 97920