import java.util.*;

public class Main {
    public static void main(String[] args){
        
        Scanner cin = new Scanner(System.in);
        
        int N = cin.nextInt();
        int list[] = new int[N];
        for(int i=0;i<N;i++){
            list[i] = cin.nextInt();
        }
        cin.close();
        int result = -1;
        int tmp = 0;
        for(int j=0;j<(int)Math.pow(10,7);j++){
            tmp = list[tmp]-1;
            if(tmp==1){
                result = j+1;
                break;
            }
        }
        System.out.println(result);
        
    }
}
/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