Перестановки

#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <vector>
#include <stdio.h>
#include <cmath>
#include <math.h>
#include <queue>
#include <stack>
#include <climits>
#include <deque>
#include <ctime>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;

#define mh() make_heap()
#define poph() pop_heap()
#define pushh() push_heap()
#define sor(n) n.begin(), n.end()
#define mp make_pair
#define files freopen("input.txt", "rt", stdin); freopen("output.txt", "wt", stdout)
#define p(T) pair<T,T>
#define znac(l) abs(l)/l
const ll ok = ll(1e9 + 7);

ll lcm(int a, int  b)
{
    ll k = a, j = b;
    while (a)
    {
        swap(a, b);
        a %= b;
    }
    return (k * j) / b;
}
int main()
{
    //files;
    int a[1001];
    ll n;
    cin >> n;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    vector <ll> kl;
    for (int i = 1; i <= n; i++)
    {
        ll var = a[i];
        ll k = 1;
        while (var != i)
        {
            var = a[var];
            k++;
        }
        kl.push_back(k);
    }
    ll hg;
    if(kl.size()>1)
    hg = lcm(kl[0], kl[1]);
    for (int i = 2; i < kl.size(); i++)
    {
        hg = lcm(hg, kl[i]);
    }
    cout << hg;
    return 0;
}