import java.io.InputStreamReader;
import java.util.Scanner;
 
public class Main {
	public static final long sosu = 1000000007;
	public static void main(String[] args) {
		try(Scanner scan = new Scanner(new InputStreamReader(System.in))){
			int N = scan.nextInt();
			int[] buttons = new int[N+1];
			
			for(int i = 1; i<=N; i++){
				buttons[i] = scan.nextInt();
			}
			
			int ans = 0;
			int on = 1;
			while(ans < N){
				on = buttons[on];
				ans++;
				if(on == 2){
					System.out.println(ans);
					return;
				}
			}
			
			System.out.println(-1);
		}
	}
}

/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