5
ababa
 8
aaabcabc
 7
abcdabc
 29
abbabbaabbbbaababbababbaabbaa
 5
baaaa
 54
dgafkhlgdhjflkdafgjldjhgkjllfallhsggaaahkaggkhgjgflsdg
 7
abcdbcd
 20
ccbbcbaabcccbabcbcaa
 11
ababcabcabc
 9
azxcvzxcv
 10
wvwlwvwwvw
 11
ababababccc
 7
dabcabc
 6
abcabd
 12
ababababvvvv
 11
jjlkalfhdhh
 6
abbbba
 8
ababcdef
 10
ababcababc
 7
ababbcc
 6
ablfab
 45
bbbbbbbabababbbaabbbbbbbbbbbbabbbabbaabbbabab
 100
mhnzadklojbuumkrxjayikjhwuxihgkinllackcavhjpxlydxcmhnzadklojbuumkrxjayikjhwuxihgkinllackcavhjpxlydxc
 5
aaaaa
 99
lhgjlskfgldjgadhdjjgskgakslflalhjfgfaaalkfdfgdkdffdjkjddfgdhalklhsgslskfdhsfjlhgajlgdfllhlsdhlhadaa
 10
adadadadad
 46
kgadjahfdhjajagdkffsdfjjlsksklgkshfjkjdajkddlj
 7
aabcdaa
 1
s
 4
ttob
 16
abcdabcdabcdabcd
 1
a
 37
lglfddsjhhaagkakadffkllkaagdaagdfdahg
 7
aabaaaa
 12
abaabaabaaba
 27
aaaaaaaaaaaaaaaaaaaaaaaaaaa
 17
abcdefggggglelsoe
 32
bbbbaaabbaabbaabbabaaabaabaabaab
 9
abbbbabbb
 10
asdasdasda
 10
bbbbbbbbbc
 11
abcabcabcab
 20
aabaabaabaabaabaabaa
 8
abcabcde
 6
abcaca
 7
aabcabc
 100
yeywsnxcwslfyiqbbeoaawtmioksfdndptxxcwzfmrpcixjbzvicijofjrbcvzaedglifuoczgjlqylddnsvsjfmfsccxbdveqgu
 16
bbbbbbaaaaaaaaaa
 77
babbaababaabbaaaabbaababbbabaaaabbabaaaaaaaabbbaaabbabbbabaababbabaabbbbaaabb
 8
aaaaaaaa
 6
ababab
 3
lsl
 12
wwvwwvwwvwwv
 10
ababababab
 8
ffffffff
 10
abcdeeeeee
 8
abbbbbba
 16
uuuuuuuuuuuuuuuu
 9
baaaabaaa
 7
zabcabc
 6
aaaaaa
 8
abcdeabc
 12
ababababbbbb
 14
abcdefgabcdepq
 6
ajkoaj
 3
aaa
 81
aaaaaababaabaaaabaaaaaaaabbabbbbbabaabaabbaaaababaabaababbbabbaababababbbbbabbaaa
 8
abcdefef
 8
abbababa
 9
abcdeabcd
 14
abcabcabcabcjj
 8
acacacac
 86
ssjskldajkkskhljfsfkjhskaffgjjkskgddfslgjadjjgdjsjfsdgdgfdaldffjkakhhdaggalglakhjghssg
 11
abcdeabcdfg
 38
asdsssdssjajghslfhjdfdhhdggdsdfsfajfas
 10
bbbbbbbaaa
 8
baaaaaaa
 5
abcbc
 8
ababcabc
 66
ldldgjllllsdjgllkfljsgfgjkflakgfsklhdhhallggagdkgdgjggfshagjgkdfld
 92
bbbbbabbbaaaabaaababbbaabbaabaaabbaabababaabbaabaabbbaabbaaabaabbbbaabbbabaaabbbabaaaaabaaaa
 10
abcabcabca
 5
aabaa
 12
abcabcabcabc
 8
aaaabcde
 8
abbbbbbb
 10
abcabcdddd
 20
abcdabcdeeeeeeeeabcd
 5
abbbb
 16
aaaaaabbaaaaaabb
 10
aaaacaaaac
 10
aaaaaaaaaa
 7
abababa
 8
aaaaaass
 7
abacbac
 36
bbabbaabbbabbbbbabaaabbabbbabaabbbab
 8
aabcabca
 10
abccaaaaba
 8
asafaass
 14
aaabcabcabcabc
 79
lsfgfhhhkhklfdffssgffaghjjfkjsssjakglkajdhfkasfdhjhlkhsgsjfgsjghglkdkalaajsfdka
 7
mabcabc
 17
ababababzabababab
 8
abababaa
 10
abcdabcefg
 17
abcdefgggggabcdef
 13
eabcdefabcdef
 8
abababab
 28
aaaaaaaaaaaaaaibfprdokxvipsq
 13
aabbbkaakbbbb
 4
abab
 9
zabcdabcd
 70
babababbabababbbabaababbababaabaabbaaabbbbaababaabaabbbbbbaaabaabbbabb
 9
abcabcabc
 2
aa
 100
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 4
aaaa
 36
babbbbababaaabbabbbaabaabbbbbbbbbbba
 9
asdfgasdf
 13
aabaabaabaabx
 95
bbaaaabaababbbabaaaabababaaaaaabbababbaabbaaabbbaaaabaaaaaaababababbabbbaaaabaabaababbbbbababaa
 5
xabab
 20
hhhhhhhhhhhhhhhhhhhh
 41
abbababbbbbabbbabaaaababaaabaabaaabbbbbbb
 8
pppppppp
 5
abcab
 10
avavavavbc
 12
aaaaaaaaaaaa
 63
jhkjhadlhhsfkadalssaaggdagggfahsakkdllkhldfdskkjssghklkkgsfhsks
 9
aaaaaaaaa
 6
abcbcd
 16
aaaaaaaaaaaaaaaa
 9
asdfpasdf
 12
aabaabaabaab
 74
ghhhfaddfslafhhshjflkjdgksfashhllkggllllsljlfjsjhfggkgjfalgajaldgjfghlhdsh
 39
jflfashaglkahldafjasagasjghjkkjgkgffgkk
 10
adcbeadcfg
 5
cabab
 6
ababbb
 99
trolnjmzxxrfxuexcqpjvefndwuxwsukxwmjhhkqmlzuhrplrtrolnjmzxxrfxuexcqpjvefndwuxwsukxwmjhhkqmlzuhrplrm
 7
abcaabc
 6
aabbbb
 87
fhjgjjagajllljffggjjhgfffhfkkaskksaalhksfllgdjsldagshhlhhgslhjaaffkahlskdagsfasfkgdfjka
 8
baaaaaab
 5
aavaa
 5
aabab

4
 8
 7
 27
 5
 54
 7
 20
 10
 9
 10
 8
 7
 6
 9
 11
 6
 7
 6
 6
 6
 43
 51
 4
 99
 7
 46
 7
 1
 4
 9
 1
 37
 7
 7
 15
 17
 31
 9
 8
 7
 9
 12
 6
 6
 7
 100
 14
 77
 5
 5
 3
 7
 7
 5
 10
 8
 9
 9
 7
 4
 8
 9
 14
 6
 3
 79
 8
 8
 9
 9
 5
 86
 11
 38
 8
 8
 5
 7
 65
 91
 8
 5
 7
 7
 8
 8
 17
 5
 9
 6
 6
 6
 6
 7
 34
 8
 10
 8
 14
 79
 7
 14
 7
 10
 17
 13
 5
 22
 13
 3
 9
 64
 7
 2
 51
 3
 36
 9
 8
 95
 5
 11
 41
 5
 5
 7
 7
 63
 6
 6
 9
 9
 7
 74
 39
 10
 5
 5
 51
 7
 6
 87
 8
 5
 5

import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.StringTokenizer;
import java.util.Map.Entry;

public class Main 
{
	public static void main(String[] args) throws NumberFormatException, IOException 
	{
		Reader s=new Reader(System.in);
		HashMap<Character, ArrayList<Integer>> map=new HashMap<Character, ArrayList<Integer>>();
		int n=s.nextInt();
		String input=s.next();
		for(int a=0;a<input.length();a++)
		{
			ArrayList<Integer> list=map.get(input.charAt(a));
			if(list==null)
			{
				list=new ArrayList<Integer>();
				list.add(a);
				map.put(input.charAt(a), list);
			}
			else
				list.add(a);
		}
		Iterator<Entry<Character, ArrayList<Integer>>> iterator=map.entrySet().iterator();
		int max=0;
		while(iterator.hasNext())
		{
			ArrayList<Integer> list=iterator.next().getValue();
			int temp=function(list, input);
			if(temp>max)
				max=temp;
		}
		if(max>0)
			System.out.println(max+1+(input.length()-max*2));
		else
			System.out.println(input.length());
	}
	public static int function(ArrayList<Integer> list, String str)
	{
		if(list.size()==1)
			return 0;
		int length=list.size();
		while(length>=2)
		{
			for(int start=0;start+length-1<list.size();start++)
			{
				int end=start+length-1;
				int leftLength=list.get(end)-list.get(start);
				if(str.length()-list.get(end)<leftLength)
					continue;
				else
				{
					if(str.substring(list.get(start), list.get(end)).equals(str.substring(list.get(end), list.get(end)+leftLength)))
						return leftLength;
					else
						continue;
				}
			}
			length--;
		}
		return 0;
	}
}
class Reader 
{
	private BufferedReader reader;
	private StringTokenizer tokenizer;
	
	public Reader(InputStream input)
	{
		reader=new BufferedReader(new InputStreamReader(input));
		tokenizer=new StringTokenizer("");
	}
	public String next() throws IOException
	{
		while(tokenizer.hasMoreTokens()==false)
		{
			tokenizer=new StringTokenizer(reader.readLine());
		}
		return tokenizer.nextToken();
	}
	public String nextLine() throws IOException
	{
		return reader.readLine();
	}
	public int nextInt() throws NumberFormatException, IOException
	{
		return Integer.parseInt(next());
	}
	public double nextDouble() throws NumberFormatException, IOException
	{
		return Double.parseDouble(next());
	}
	public long nextLong() throws NumberFormatException, IOException
	{
		return Long.parseLong(next());
	}
}

