#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define REP(i, n)           for(int(i)=0;(i)<(n);++(i))
const int MOD = 1000000007;

int N, a[51], b[51];
bool done[51];

int loop_size(int i){
	if(done[i]) return 0;
    done[i] = true;
	return loop_size(a[i]) + 1;
}

int main(){
    cin >> N;
    REP(i,N){
        cin >> a[i]; a[i]--;
        b[i] = -1;
    }
    int k = 0;
    REP(i,N){
	    if(done[i]) continue;
        if(loop_size(i)%2 == 0) k ^= 1;
    }

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