import java.util.*;

public class Main {

    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        int[] array = new int[n];
        for (int i = 0; i < n; i++) {
            array[i] = sc.nextInt();
        }

        boolean[] visit = new boolean[n];

        int current = 0;
        int count = 0;

        visit[1] = true;

        //ボタンを押す
        while (true) {
            current = array[current] - 1;
            count++;
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (visit[current]) {
                System.out.println("-1");
                return;
            }
            visit[current] = true;
        }
    }

}
/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