import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner scan = new Scanner(System.in);
        int N = scan.nextInt();
        int[] num = new int[N];
        
        for(int i = 0; i < N; i++) {
            num[i] = scan.nextInt();
        }
        
        boolean[] lightON = new boolean[N];
        int buttonNum = num[0];
        lightON[0] = true;

        int count = 0;
        int answer = -1;
        
        while(true) {
            lightON[buttonNum-1] = true;
            count++;
            
            if(lightON[1] == true) {
                answer = count;
                break;
            }
            
            buttonNum = num[buttonNum-1];
            if(lightON[buttonNum-1] == true) {
                break; 
            }
        }
        System.out.println(answer);
    }
}

/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