#include <iostream>
#include <cmath>
#include <cstdio>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <string.h>
#include <map>
#include <fstream>
#include <functional>
#include <bitset>
#include <iomanip>
#include <stack>
#include <set>
#include <climits>
#define MAX_N 200010
#define PI 3.141592653589
#define ESP 1e-20
#define BS 10
#define MOD 1000000007 
#define ZERO 10001
#define YJSNPI 810
#define INF (1LL << 50)
#define ADD(a, b) a = (a + (ll)b) % MOD
#define MUL(a, b) a = (a * (ll)b) % MOD
#define MAX(a, b) a = max(a, b)
#define MIN(a, b) a = min(a, b)

using namespace std;

typedef pair<int, int> pi;
typedef long long ll;

int N;
int goal[100], used[100];
int cnt[100];

int loop(int at) {
	if(used[at]) return 0;
	used[at] = true;
	return loop(goal[at]) + 1;
}

int main() {
	cin >> N;
	for(int i = 0; i < N; i++) {
		cin >> goal[i]; goal[i]--;
	}
	for(int i = 0; i < N; i++) {
		if(!used[i]) cnt[loop(i)]++;
	}
	for(int i = 0; i <= N; i += 2) {
		if(cnt[i] % 2 != 0) {
			cout << "No" << endl; return 0;
		}
	}
	cout << "Yes" << endl;
}