int minimumSwaps(int n, const vector<int>& arr) {
    vector<vector<int>> cycles;
    vector<bool> visited(n+1);
    for (int i = 1; i <= n; ++i) {
        if (visited[arr[i]]) continue;
        cycles.push_back({arr[i]});
        int travel = arr[i];
        visited[travel] = true;
        while (arr[travel] != cycles.back()[0]) {
            cycles.back().push_back(arr[travel]);
            travel = arr[travel];
            visited[travel] = true;
        }
    }
    int moves = 0;
    for (vector<int> cycle : cycles) moves = moves + cycle.size() - 1;
    return moves;
}

int main()
{
    int n, k;
    vector<int> arr = {-1};
    cin >> n;
    for (int i=1; i <= n; ++i) {
        cin >> k;
        arr.push_back(k);
    }
    cout << minimumSwaps(n, arr);
}