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.*;
import java.util.*;
import static java.lang.Math.*;
import static java.util.Arrays.*;

public class CF {

    public static void main(String[] args) throws IOException {
        FastScanner in = new FastScanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        int n = in.nextInt();
        String ch = in.next();
        int min = Integer.MAX_VALUE;
        for (int i = 0; i < ch.length(); i++) {
            for (int j = i + 1; j < ch.length(); j++) {
                if (ch.substring(i, j).equals(ch.substring(j, min(2 * j - i, ch.length())))) {
                    min = min(min, j + ch.length() - (2 * j - i - 1));
                }
            }
        }
        if (min == Integer.MAX_VALUE) {
            min = ch.length();
        }
        out.println(min);
        out.close();
    }

    static class FastScanner {

        private BufferedReader in;
        private String[] line;
        private int index;
        private int size;

        public FastScanner(InputStream in) throws IOException {
            this.in = new BufferedReader(new InputStreamReader(in));
            init();
        }

        public FastScanner(String file) throws FileNotFoundException {
            this.in = new BufferedReader(new FileReader(file));
        }

        private void init() throws IOException {
            line = in.readLine().split(" ");
            index = 0;
            size = line.length;
        }

        public int nextInt() throws IOException {
            if (index == size) {
                init();
            }
            return Integer.parseInt(line[index++]);
        }

        public long nextLong() throws IOException {
            if (index == size) {
                init();
            }
            return Long.parseLong(line[index++]);
        }

        public float nextFloat() throws IOException {
            if (index == size) {
                init();
            }
            return Float.parseFloat(line[index++]);
        }

        public double nextDouble() throws IOException {
            if (index == size) {
                init();
            }
            return Double.parseDouble(line[index++]);
        }

        public String next() throws IOException {
            if (index == size) {
                init();
            }
            return line[index++];
        }

        public String nextLine() throws IOException {
            if (index == size) {
                init();
            }
            StringBuilder sb = new StringBuilder();
            for (int i = index; i < size; i++) {
                sb.append(line[i]).append(" ");
            }
            return sb.toString();
        }

        private int[] nextIntArray(int n) throws IOException {
            int[] tab = new int[n];
            for (int i = 0; i < tab.length; i++) {
                tab[i] = nextInt();
            }
            return tab;
        }

        private double[] nextDoubleArray(int n) throws IOException {
            double[] tab = new double[n];
            for (int i = 0; i < tab.length; i++) {
                tab[i] = nextDouble();
            }
            return tab;
        }

    }

}
