#include <bits/stdc++.h>

using namespace std;

int main () {
	ios::sync_with_stdio(false);

	long long n;
	
	while ( cin >> n ) {
		vector < pair<bool,long long >> in;
		for ( long long i = 0; i < n; ++i ) {
			long long x;
			cin >> x;
			in.push_back({(x-1==i),x-1});
					
		}
		long long cnt = 0;
		for (long long i =0;i<n;++i){
			if (!in[i].first) {
				long long pom=0;
				long long j=in[i].second;
				while (j!=i){
					in[j].first=true;
					j=in[j].second;
					++pom;
				}
				in[i].first=true;
				cnt+=pom;
			}	
			
		}
		
		cout << cnt << endl;
		
	}/*
		while ( end != 0) {
			ctr = false;
			
			long long max = in[0], mi = 0, sorted = 0;
			for ( long long i = 0; i < end; ++i ) {
				if ( in[i] > max ) {
					max = in[i];
					mi = i;
				}
				
				if ( in[i] != ( i + 1 ) )
					sorted = i; 			
			}
			
			if ( mi != ( end - 1 ) ) {
				swap(in[mi], in[end-1]);
				++cnt;
			}
			//--end;
			end = sorted;			
		}
		
		cout << cnt << endl;
	
	}*/
	
	return 0;
}