import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		boolean isTwo = false;
		int tmp=0;
		Scanner in = new java.util.Scanner(System.in);
		int N = in.nextInt();
		int[] array = new int[N];
		boolean[] flags = new boolean[N];
		for(int i=0; i<array.length; i++){
			tmp = in.nextInt();
			if(tmp == 2){
				isTwo = true;
			}
			array[i] = tmp;
		}
		if(isTwo == false){
			System.out.print("-1");
			System.exit(0);
		}
		int count = 0;
		count++;
		int now = 1;
		while(array[now-1] != 2){
			if(flags[now-1] == true){
				System.out.print("-1");
				System.exit(0);
			}
			flags[now-1] = true;
			now = array[now -1];
			count++;
		}
		System.out.print(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