#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <math.h>
#include <cmath>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <iomanip>
#include <climits>
#include <functional>
#include <cassert>
#include <tuple>
using namespace std;
using ll = long long;

int N;
int P[101];

int main() {

    cin >> N;
    for(int i = 1; i <= N; ++i) cin >> P[i];

    int cnt = 0;
    for(int i = 1; i < N; ++i) {
        if(P[i] == i) continue;
        for(int j = i+1; j <= N; ++j) {
            if(P[j] == i) {
                swap(P[i],P[j]);
                cnt++;
                break;
            }
        }
    }

    cout << cnt << endl;

}