#include <cstdlib>
#include <iostream>

using namespace std;

int main(int argc, char** argv) {
    
    ios::sync_with_stdio(false);
    
    
    while(cin.good()){
        int numCnt, swaps = 0;
        
        cin >> numCnt;
        
        
        if (!cin.good())
            return 0;
        
        int * index = new int[numCnt+1];
        int * nums = new int[numCnt+1];
        
        for(int i=1; i<=numCnt; ++i){
            int num;
            cin >> num;
            index[num] = i;
            nums[i] = num;
        }
        
        for(int i=1; i<=numCnt; ++i){
            if (index[i] == i) {
                continue;
            }
            int a,b, aIndex, bIndex;
            
            a = nums[i];
            b = i;
            aIndex = index[a];
            bIndex = index[b];
            
            nums[bIndex] = a;
            nums[aIndex] = b;
            
            index[a] = bIndex;
            index[b] = aIndex;

            swaps++;
        }
        
        cout << swaps << endl;
    }

    return 0;
    
}