import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Deque;//push poll peek
import java.util.ArrayDeque;
import java.util.Queue;//add poll peek
import java.util.ArrayDeque;
import java.math.BigDecimal;

class Main{

	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		int[] a = new int[n];
		for(int i = 0;i < n;i++){
			a[i] = Integer.parseInt(br.readLine());
		}
		int count = 0;
		int k = 0;
		int l;
		boolean flag = false;
		l = a[0] - 1;
		count += 1;
		while(count <= n){
			if(l == 1){
				flag = true;
				System.out.println(count);
				break;
			}
			l = a[l] - 1;
			count += 1;
		}
		if(!flag){
			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