#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll inf=14449999999999999;
ll mod=998244353;
int main(){
    ll n;
    cin >> n;
    vector<ll>p(n);
    vector<ll>c(n);
    for (ll i = 0; i < n; i++)
    {
        cin >> p[i];
        p[i]--;
        c[p[i]]=i;
    }
    ll ans=0;
    for (ll i = 0; i < n; i++)
    {
        if (c[i]!=i)
        {
            ans+=1;
            ll x=i,y=c[i],a=p[i],b=p[c[i]];
            p[y]=p[i];
            p[i]=i;
            c[a]=y;
            c[i]=i;
        }
    }
    cout << ans << endl;
}