/* -*- coding: utf-8 -*-
 *
 * 100.cc: No.100 直列あみだくじ - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 50;

/* typedef */

/* global variables */

int as[MAX_N], lss[MAX_N + 1];
bool used[MAX_N];

/* subroutines */

/* main */

int main() {
  int n;
  cin >> n;

  for (int i = 0; i < n; i++) (cin >> as[i]), as[i]--;

  for (int i = 0; i < n; i++)
    if (! used[i]) {
      used[i] = true;
      int l = 1;
      for (int j = as[i]; j != i; j = as[j])
	used[j] = true, l++;
      if (! (l & 1)) lss[l]++;
      //printf("i=%d: l=%d\n", i, l);
    }

  bool ok = true;
  for (int i = 2; ok && i <= n; i += 2)
    if (lss[i] & 1) ok = false;

  cout << (ok ? "Yes" : "No") << endl;
  return 0;
}