#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;

using u128 = unsigned __int128;
using i128 = __int128;

struct DSU {
    std::vector<int> f;
    DSU() {}
    DSU(int n) {
        init(n);
    }
    void init(int n) {
        f.resize(n);
        std::iota(f.begin(), f.end(), 0);
    }
    int find(int x) {
        while (x != f[x]) {
            x = f[x] = f[f[x]];
        }
        return x;
    }
    bool merge(int x, int y) {
        x = find(x);
        y = find(y);
        if (x == y) {
            return false;
        }
        f[y] = x;
        return true;
    }
};

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int N;
    std::cin >> N;

    DSU dsu(N);
    int ans = 0;
    for (int i = 0; i < N; i++) {
        int j;
        std::cin >> j;
        j--;
        if (!dsu.merge(i, j)) {
            ans++;
        }
    }
    std::cout << ans << '\n';

    return 0;
}