#include <iostream>
using namespace std;

#define maxN 10001

int nums[maxN] = {0};
int nums_2[maxN] = {0};
int N;

void swap(int &a, int &b)
{
    int temp = a;
    a = b;
    b = temp;
}

int main()
{
    int count = 0;
    cin >> N;
    for (int i = 1; i <= N; i++)
    {
        cin >> nums_2[i];
        nums[nums_2[i]] = i;
    }
    for (int i = 1; i <= N; i++)
    {
        if (i == nums[i])
            continue;
        else
        {
            count++;
            swap(nums_2[nums[i]], nums_2[i]);
            nums[nums_2[nums[i]]] = nums[i];
            nums[i] = i;
        }
    }
    cout << count;
}