#include<bits/stdc++.h>
using namespace std;
int main(){
int n,sum = 0;
cin >> n;
int arr[n + 1];
for(int i = 1;i <= n;i ++)
cin >> arr[i];
for(int i = 1; i <= n; i++)
while(arr[i] != i)
swap(arr[i],arr[arr[i]]),sum++;
cout<<sum;
return 0;
}