#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)n;++i)
#define each(a,b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout<<" "<<kbrni;cout<<endl
#define smap(m) cout<<#m<<":";each(kbrni,m)cout<<" {"<<kbrni.first<<":"<<kbrni.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int>P;

const int MAX_N = 1000005;

bool use[MAX_N];
set<int> st;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector<int> vec(n);
    rep(i,n){
        cin >> vec[i];
        vec[i]--;
    }
    rep(i,n){
        if(!use[vec[i]]){
            int cnt = 0;
            int nw = vec[i];
            use[vec[i]] = true;
            while(1){
                cnt++;
                if(vec[nw] == vec[i]){
                    break;
                }else{
                    use[vec[nw]] = true;
                    nw = vec[nw];
                }
            }
            if(cnt % 2 == 0){
                if(st.count(cnt) > 0){
                    st.erase(cnt);
                }else{
                    st.insert(cnt);
                }
            }
        }
    }
    if(st.size() == 0){
        cout << "Yes\n";
    }else{
        cout << "No\n";
    }
    return 0;
}