import java.util.Scanner;
public class Main {

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

		for(int i=0; i<N; i++) {
			a[i] = sc.nextInt();
		}

		int k = a[0];
		int count = 0;

		while(k != 2 && count <= N) {
		k = a[k-1];
		count += 1;
		}

		if(k==2) {
			System.out.println(count + 1);
		}else {
			System.out.println(-1);
		}

	}

} import java.util.Scanner; Scanner java.util public class Main {

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

		for(int i=0; i<N; i++) {
			a[i] = sc.nextInt();
		}

		int k = a[0];
		int count = 0;

		while(k != 2 && count <= N) {
		k = a[k-1];
		count += 1;
		}

		if(k==2) {
			System.out.println(count + 1);
		}else {
			System.out.println(-1);
		}

	}

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] a = new int[N];

		for(int i=0; i<N; i++) {
			a[i] = sc.nextInt();
		}

		int k = a[0];
		int count = 0;

		while(k != 2 && count <= N) {
		k = a[k-1];
		count += 1;
		}

		if(k==2) {
			System.out.println(count + 1);
		}else {
			System.out.println(-1);
		}

	} main {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int[] a = new int[N];

		for(int i=0; i<N; i++) {
			a[i] = sc.nextInt();
		}

		int k = a[0];
		int count = 0;

		while(k != 2 && count <= N) {
		k = a[k-1];
		count += 1;
		}

		if(k==2) {
			System.out.println(count + 1);
		}else {
			System.out.println(-1);
		}

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int[] a = new int[N]; a new int[N] N for(int i=0; i<N; i++) {
			a[i] = sc.nextInt();
		} int i=0; int i=0; i 0 i<N i N i++ i++ i {
			a[i] = sc.nextInt();
		} {
			a[i] = sc.nextInt();
		} a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc int k = a[0]; k a[0] a 0 int count = 0; count 0 while(k != 2 && count <= N) {
		k = a[k-1];
		count += 1;
		} k != 2 && count <= N k != 2 k 2 count <= N count N {
		k = a[k-1];
		count += 1;
		} k = a[k-1] k a[k-1] a k-1 k 1 count += 1 count 1 if(k==2) {
			System.out.println(count + 1);
		}else {
			System.out.println(-1);
		} k==2 k 2 {
			System.out.println(count + 1);
		} System.out.println(count + 1) System.out.println System.out System System.out count + 1 count 1 {
			System.out.println(-1);
		} System.out.println(-1) System.out.println System.out System System.out -1 1 String[] args args public class Main {

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

		for(int i=0; i<N; i++) {
			a[i] = sc.nextInt();
		}

		int k = a[0];
		int count = 0;

		while(k != 2 && count <= N) {
		k = a[k-1];
		count += 1;
		}

		if(k==2) {
			System.out.println(count + 1);
		}else {
			System.out.println(-1);
		}

	}

} public class Main {

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

		for(int i=0; i<N; i++) {
			a[i] = sc.nextInt();
		}

		int k = a[0];
		int count = 0;

		while(k != 2 && count <= N) {
		k = a[k-1];
		count += 1;
		}

		if(k==2) {
			System.out.println(count + 1);
		}else {
			System.out.println(-1);
		}

	}

} Main
import java.util.Scanner;
public class Main {

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

		for(int i=0; i<N; i++) {
			a[i] = sc.nextInt();
		}

		int k = a[0];
		int count = 0;

		while(k != 2 && count <= N) {
		k = a[k-1];
		count += 1;
		}

		if(k==2) {
			System.out.println(count + 1);
		}else {
			System.out.println(-1);
		}

	}

}
