import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line = br.readLine();
        int n = Integer.parseInt(line);
        int[] a = new int[n];
        int k = 0;
        int count = 1;
        boolean fin = false;
        for(int i = 0; i < n; i++) {
            a[i] = Integer.parseInt(br.readLine());
        }
        for(int i = 0; i < n; i++) {
            if(a[k] != 2 && !fin) {
                count++;
                k = a[k] - 1;
            } else {
                fin = true;
            }
        }
        if(fin) {
            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