#include<bits/stdc++.h>
#define N 1000005
#define ll long long
#define endl '\n'
using namespace std;
const ll MAXN=1e8+9,MINN=-1e8+9;
int n,m,i,j,k,l,r,t,ans=MAXN,a[N],b[N],vis[N];
int dfs(int x){
	if(vis[x]!=0&&b[x]==j){
		return k-vis[x]+1;
	}else if(vis[x]!=0){
		return MAXN;
	}
	vis[x]=++k;
	b[x]=j;
	dfs(a[x]);
}
int main(){
	cin>>n;
	for(i=1;i<=n;i++){
		cin>>a[i];
	}
	for(i=1;i<=n;i++){
		if(!vis[i]){
			j++;
			k=0;
			r=dfs(i);
			if(r<ans){
				ans=r;
			}
		}
	}
	cout<<ans<<endl;
	return 0;
}