#include using namespace std; typedef long long ll; typedef pair p_ll; template void debug(T itr1, T itr2) { auto now = itr1; while(now=0; i--) const ll MOD = pow(10,9)+7; const ll LLINF = pow(2,61)-1; const int INF = pow(2,30)-1; vector fac; void c_fac(int x=pow(10,6)+10) { fac.resize(x,true); rep(i,x) fac[i] = i ? (fac[i-1]*i)%MOD : 1; } ll inv(ll a, ll m=MOD) { ll b = m, x = 1, y = 0; while (b!=0) { int d = a/b; a -= b*d; swap(a,b); x -= y*d; swap(x,y); } return (x+m)%m; } ll nck(ll n, ll k) { return fac[n]*inv(fac[k]*fac[n-k]%MOD)%MOD; } ll gcd(ll a, ll b) { if (a par, s; UnionFind(int N) : par(N), s(N) { rep(i,N) { par[i] = i; s[i] = 1; } } int root(int x) { return par[x]==x ? x : par[x] = root(par[x]); } int size(int x) { return par[x]==x ? s[x] : s[x] = size(root(x)); } void unite(int x, int y) { int rx=root(x), ry=root(y); if (rx!=ry) { s[rx] += s[ry]; par[ry] = rx; } } bool same(int x, int y) { int rx=root(x), ry=root(y); return rx==ry; } }; // ---------------------------------------------------------------------- // ---------------------------------------------------------------------- int main() { ll N; cin >> N; ll a[N]; rep(i,N) { cin >> a[i]; a[i]--; } UnionFind uf(N); rep(i,N) uf.unite(i,a[i]); ll one = 0, o = 0, e = 0; rep(i,N) { if (i==uf.root(i)) { if (uf.size(i)==1) one++; else if (uf.size(i)%2) o++; else e++; } } // cout << one << " " << o << " " << e << endl; string result = one%2==0&&e==0 ? "Yes" : "No"; cout << result << endl; return 0; }