#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define all(c) c.begin(),c.end()
#define pb push_back
#define fs first
#define sc second
#define show(x) cout << #x << " = " << x << endl
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
using namespace std;
int N,a[50];
bool vis[50];
int c;
void dfs(int x){
	if(vis[x]) return;
	c++;
	vis[x]=1;
	dfs(a[x]);
}
int cnt[51];
int main(){
	cin>>N;
	rep(i,N) cin>>a[i],a[i]--;
	rep(i,N) if(!vis[i]){
		c=0;
		dfs(i);
		cnt[c]++;
	}
	rep(i,51) if(i%2==0&&cnt[i]%2==1){
		puts("No");
		return 0;
	}
	puts("Yes");
}