#include <bits/stdc++.h>
using namespace std;
const int N = 11100000;
char s[N];
int pre[N];
int main() 
{
    int n; scanf("%d%s", &n, s + 1);
    memset(pre, 0, sizeof(pre));
    for(int i = 1, j = pre[i]; i < n; i++, j = pre[i]) 
    {
        while(j > 0 && s[i + 1] != s[j + 1]) j = pre[j];
        if(s[i + 1] == s[j + 1]) pre[i + 1] = j + 1;     
    }
    printf("%d\n", n - pre[n]);
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
const int N=11100000;
char s[N];
int pre[N];
int main() 
{
	int n; scanf("%d%s",&n,s+1);
    memset(pre,0,sizeof(pre));
    for(int i=1,j=pre[i]; i<n; i++,j=pre[i]) 
	{
        while( j>0 && s[i+1]!=s[j+1]) j=pre[j];
        if(s[i+1]==s[j+1])pre[i+1]=j+1;     
    }
    printf("%d\n",n-pre[n]);
    return 0;
}