#include <iostream>
#include <vector>
using namespace std;
int main() {
	int n, k, j, z, c, el;
	c = 0;
	k = 0;
	z = 0;
	std::vector <int> copy;
	std::vector <int> res;
	std::cin >> n;
	for (int i = 0; i < n; i++) {
		std::cin >> el;
		copy.push_back(el);
		res.push_back(el);
	}
while (c != 1) {
for (int i = 0; i < n; ++i) {
	j = copy[i];
	res[i] = copy[j]; }
	for (int i = 0; i < n; ++i) {
	copy[i] = res[i]; }
	for (int i = 0; i < n; ++i) {
		if (copy[i] == i) ++z; }
		if (z == n) c = 1;
		z = 0;
		k += 1;
}
std::cout << k;
	return 0;
}