import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int[] a = new int[n];
        boolean[] isA = new boolean[n];
        for (int i = 0; i < n; i++) {
            a[i] = scanner.nextInt();
        }
        int count = 0;
        int i = 0;
        while(i != 1 && !isA[i]){
            isA[i] = true;
            i = a[i]-1;
            count++;
        }
        if (i == 1){
            System.out.println(count);
        }else {
            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