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.*;

public class Main {
    static String s;
    public static int contains(String currStr){
        int l = 0; int r = currStr.length()-1;
        int cnt = 0; int idx = 0;
        while(r+idx < s.length()){
            if(s.substring(l+idx, r+idx+1).equals(currStr)){
                cnt++;
                idx += currStr.length();
            }
            else idx++;
        }
        return cnt;
    }
    public static void main(String[] args) throws IOException {
        int n = sc.nextInt();
        s = sc.nextLine();
        int bestAns = (int) 1e9;
        for (int i = 0; i < s.length(); i++) {
            for (int j = i+1; j < s.length(); j++) {
                String currStr = s.substring(i, j+1);
                int cnt = contains(currStr);
                int currAns = currStr.length() + (cnt-1) + (s.length()-cnt*currStr.length());
                bestAns = Math.min(currAns, bestAns);
            }
        }
        pw.println(bestAns);

        pw.close();
    }

    public static void pairSort(Pair[] arr) {
        ArrayList<Pair> l = new ArrayList<>();
        for (Pair i : arr) l.add(i);
        Collections.sort(l);
        for (int i = 0; i < arr.length; i++) {
            arr[i] = l.get(i);
        }
    }
    public static void longSort(long[] arr) {
        ArrayList<Long> l = new ArrayList<>();
        for (long i : arr) l.add(i);
        Collections.sort(l);
        for (int i = 0; i < arr.length; i++) {
            arr[i] = l.get(i);
        }
    }
    public static void intSort(int[] arr) {
        ArrayList<Integer> l = new ArrayList<>();
        for (int i : arr) l.add(i);
        Collections.sort(l);
        for (int i = 0; i < arr.length; i++) {
            arr[i] = l.get(i);
        }
    }

    static class Scanner {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if (x.charAt(0) == '-') {
                neg = true;
                start++;
            }
            for (int i = start; i < x.length(); i++)
                if (x.charAt(i) == '.') {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                } else {
                    sb.append(x.charAt(i));
                    if (dec)
                        f *= 10;
                }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg ? -1 : 1);
        }

        public boolean ready() throws IOException {
            return br.ready();
        }

        public int[] nextIntArr(int n) throws IOException {
            int[] arr = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = Integer.parseInt(next());
            }
            return arr;
        }

        public long[] nextLongArr(int n) throws IOException {
            long[] arr = new long[n];
            for (int i = 0; i < n; i++) {
                arr[i] = Long.parseLong(next());
            }
            return arr;
        }

    }
    static class Pair implements Comparable<Pair>{
        int first, second;
        public Pair(int first, int second){
            this.first = first; this.second = second;
        }

        @Override
        public int compareTo(Pair p2) {
            return first - p2.first;
        }

        @Override
        public String toString() { return "("+ first + "," + second + ')'; }

    }

    static PrintWriter pw = new PrintWriter(System.out);
    static Scanner sc = new Scanner(System.in);
    static final int MOD = (int) 1e9 + 7;
    static Random random = new Random();
}