#include<bits/stdc++.h>
using namespace std;

typedef long long int ll;
typedef unsigned long long int llu;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pair<int, int> > vii;

#define rrep(i, m, n) for(int i=m; i<n;  i++)
#define erep(i, n)    for(int i=1; i<=n; i++)
#define  rep(i, n)    for(int i=0; i<n;  i++)
#define rrev(i, m, n) for(int i=n-1; i>=m; i--)
#define erev(i, n)    for(int i=n; i>=1; i--)
#define  rev(i, n)    for(int i=n-1; i>=0; i--)
#define EACH(v)       (v).begin(), (v).end()
#define CNT(a, n, x)  (upper_bound(a, a+n, x)-lower_bound(a, a+n, x))
#define minup(m, x)   (m=min(m, x))
#define maxup(m, x)   (m=max(m, x))
#define mp            make_pair
#define pb            push_back

#define INF 1000000000
#define MOD 1000000009
#define EPS 1E-9

#define MAX_N 50

int n;
int a[MAX_N];
bool used[MAX_N];
bool res = true;
int num[MAX_N+1];

int main()
{
  cin >> n;
  rep(i, n) cin >> a[i];
  rep(i, n) a[i] -= 1;

  rep(i, n) if(!used[i]){
    int cnt = 0;
    for(int next=i; !used[next]; next=a[next]){
      //      cout << next + 1 << " ";
      used[next] = true;
      cnt += 1;
    }
    num[cnt] += 1;
    //    cout << " ---- " << cnt << endl;
    //    if(cnt%2 == 0) res = !res;
  }

  erep(i, n) if(i%2 == 0) if(num[i]%2 == 1) res = false;

  puts(res ? "Yes" : "No");

  return 0;
}