#include<cstdio>
#include<iostream>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;
const int MAX=200010;
int next[MAX],pre[MAX]={0},visit[MAX]={0};
int empty(int x)//清边 
{
    int y,z;
    while(pre[x]==0)
    {
        visit[x]=1;
        pre[next[x]]--;
        y=next[x];
        next[x]=0;
        x=y;
    }
    
    return 0;   
}
int dfs(int x)//找环
{
    int y,z=0;
    while(next[x]!=0)
    {
        z++;
        y=next[x];
        next[x]=0;
        x=y;
    }
    return z;
 } 
int main()
{
    int i,j,k,l,m,n,ans=0x7ffffff;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&next[i]);
        pre[next[i]]++;
        }   
    for(int i=1;i<=n;i++)
    {
        if((pre[i]==0)&&(visit[i]!=1))
        {
            empty(i);
        }
    }
/*      for(int i=1;i<=n;i++)
    {
        cout<<next[i]<<" "<<pre[i]<<" "<<visit[i]<<endl;
    }*/
    for(int i=1;i<=n;i++)
    {
        if(next[i]!=0)
        {
            ans=min(ans,dfs(i));
        }
    }
        cout<<ans;
        return 0;
            
 }