
import java.util.Scanner;


public class Main{
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        int n=in.nextInt();
        int[]list=new int[n+1];
        boolean[]isVisit=new boolean[n+1];
        for (int i = 1; i <= n; i++) {
           list[i]= in.nextInt();
        }
        int count=0;
        int start=1;
        
        while(true){
           if(isVisit[start]){
            System.out.println(-1);
            return;
        }
            isVisit[start]=true;
        
        if(start==2)
            break;
       
            start=list[start];
        count++;
        }
        
        
        System.out.println(count);
    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz