#include<bits/stdc++.h>
using namespace std;
 
#define ll long long
 
void solve(){
    int n;
    cin>>n;
    vector<int>v(n+1);
    for(int i=1;i<=n;i++)cin>>v[i];
    unordered_map<int,int>mp;
    for(int i=1;i<=n;i++) mp[v[v[v[i]]]]++;
    ll p=0;
    for(auto &i:mp){
        ll a=i.second;
        p+=(a*(a-1))/2;
    }
    cout<<p<<"\n";
}
 
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    solve();
    return 0;
}

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