#include <bits/stdc++.h>

int main () {
    
    int n;
    std::cin >> n;
    
    std::vector<int> nums(n);
    for (auto& val : nums) {
        std::cin >> val;
        --val;
    }
    
    int ans = 0;
    for (int start = 0; start < n; ++start) {
        if (nums[start] == -1)
            continue;
            
        int streak = 0;
        for (int cur = start; nums[cur] != -1;) {
            ++streak;
            const int nei = nums[cur];
            nums[cur] = -1;
            cur = nei;
        }
        
        ans += streak - 1;
    }
    
    std::cout << ans << "\n";
    
    return 0;
}