建议降橙！！！！

#include<bits/stdc++.h>
#define ll long long
#define un unsigned
#define int long long
#define db double
#define inf 1000000000000000
#define st string
#define ct const
#define xh(a,b,c) for(int a=b;a<=c;a++)
#define wx while(1)
#define dn(a,b,c) for(int a=b;a>=c;a--)
using namespace std;
ll max(ll x,ll y){
   return x>y?x:y;
}
ll min(ll x,ll y){
   return x<y?x:y;
}
int n,a[10010];
int ans;
signed main(){
	cin>>n;
	xh(i,1,n)cin>>a[i];
	xh(i,1,n){
		if(a[i]==i)continue;
		xh(j,i+1,n){
			if(a[j]==i){
				swap(a[i],a[j]);
				++ans;
				break;
			}
		}
	}
	cout<<ans;
	return 0;
}