import java.util.ArrayList;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		ArrayList<Integer> num = new ArrayList<Integer>();
		ArrayList<String> param = new ArrayList<String>();
		int system = 0; // 文字の空白区切り　0:ON　1:OFF

		while (sc.hasNext()) {
			if (sc.hasNextInt()) {
				num.add(sc.nextInt());
			} else {
				if(system==0) param.add(sc.next());
				if(system==1) param.add(sc.nextLine());
			}
		}
		Method(num, param);
	}

	static void Method(ArrayList<Integer> num, ArrayList<String> param) {
		
		int now = 1;
		int count = 0;
		
		while(true){
			now = num.get(now);
			count++;
			if(now == 2) break;
			if(count == num.size()){
				count = -1;
				break;
			}
		}
		
		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