#include <bits/stdc++.h>
class DisjointSets
{
public:
    DisjointSets(const std::size_t v) : parent(v), rank(v, 0), size(v, 1) { std::iota(parent.begin(), parent.end(), 0); }
    bool same(const std::size_t a, const std::size_t b) { return find(a) == find(b); }
    void unite(std::size_t a, std::size_t b)
    {
        a = find(a), b = find(b);
        if (a == b) { return; }
        if (rank[a] < rank[b]) { std::swap(a, b); }
        if (rank[a] == rank[b]) { rank[a]++; }
        size[a] += size[b], parent[b] = a;
    }
    std::size_t getSize(const std::size_t a) { return size[find(a)]; }
    std::size_t find(const std::size_t a) { return parent[a] == a ? a : parent[a] = find(parent[a]); }

private:
    std::vector<std::size_t> parent, rank, size;
};
int main()
{
    int N;
    std::cin >> N;
    DisjointSets uf(N);
    for (int i = 0, a; i < N; i++) { std::cin >> a, uf.unite(i, a - 1); }
    std::vector<bool> used(N, false);
    std::map<int, int> mp;
    int even = 0;
    for (int i = 0; i < N; i++) {
        if (not used[uf.find(i)]) {
            used[uf.find(i)] = true;
            if (uf.getSize(i) % 2 == 0) { mp[uf.getSize(i)]++; }
        }
    }
    for (const auto& p : mp) {
        if (p.second % 2 != 0) { return std::cout << "No" << std::endl, 0; }
    }
    std::cout << "Yes" << std::endl;
    return 0;
}