#include<algorithm>
#include<iostream>
#include<vector>
#include<map>
#include<cassert>
using namespace std;
using ll = long long;

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin>>n;
    vector<int> p(n);
    for(int i = 0;i<n;i++){
        cin>>p[i];
        p[i]--;
    }
    vector<int> idx(n,0);
    for(int i = 0;i<n;i++) idx[p[i]] = i;
    ll ans = 0;
    for(int i = 0;i<n;i++){
        while(true){
            if(p[i]==i) break;
            int want = idx[p[i]-1];
            swap(p[i],p[want]);
            idx[p[i]] = i;
            idx[p[want]] = want;
            ans++;
        }
    }
    cout<<ans<<endl;
}