[백준 14656] 조교는 새디스트야!!

#include <iostream>
#include <algorithm>
using namespace std;
 
int main(void) {
    int n, cnt = 0;
 
    cin >> n;
    for (int i = 1; i <= n; i++) {
        int a;
        cin >> a;
        if (a != i) {
            cnt++;
        }
    }
 
    cout << cnt << endl;
}