#include<iostream>
using namespace std;

const int N = 100010, M = 100010;

int n;
char p[N];
int ne[N];

int main()
{
	cin >> n >> p + 1;
	for (int i = 2,j = 0;i <= n;i++)
	{
		while (j>0 && p[i] != p[j + 1]) j = ne[j];
		if (p[i] == p[j + 1]) j++;
		ne[i] = j;
	}
	//for (int k = 1;k <= n;k++) printf("%d ", ne[k]);
	
	printf("%d\n", n - ne[n]);
	return 0;
}