#include using namespace std; typedef long long int ll; typedef unsigned long long int llu; typedef pair pii; typedef vector vi; typedef vector > vii; #define rrep(i, m, n) for(int i=m; 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; 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]){ used[next] = 1; cnt += 1; } if(cnt%2 == 0) res = !res; } puts(!res ? "Yes" : "No"); return 0; }