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 now =1;
		int count =0;
		while (now!=2) {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		}
		if (count>N) {
			System.out.println(-1);
		} else {
			System.out.println(count);
		}
	}
} 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 now =1;
		int count =0;
		while (now!=2) {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		}
		if (count>N) {
			System.out.println(-1);
		} else {
			System.out.println(count);
		}
	}
} 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 now =1;
		int count =0;
		while (now!=2) {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		}
		if (count>N) {
			System.out.println(-1);
		} else {
			System.out.println(count);
		}
	} 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 now =1;
		int count =0;
		while (now!=2) {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		}
		if (count>N) {
			System.out.println(-1);
		} else {
			System.out.println(count);
		}
	} 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 now =1; now 1 int count =0; count 0 while (now!=2) {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		} now!=2 now 2 {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		} if (count>N) {
				break;
			} count>N count N {
				break;
			} break; now = a[now-1] now a[now-1] a now-1 now 1 count++ count if (count>N) {
			System.out.println(-1);
		} else {
			System.out.println(count);
		} count>N count N {
			System.out.println(-1);
		} System.out.println(-1) System.out.println System.out System System.out -1 1 {
			System.out.println(count);
		} System.out.println(count) System.out.println System.out System System.out count 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 now =1;
		int count =0;
		while (now!=2) {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		}
		if (count>N) {
			System.out.println(-1);
		} else {
			System.out.println(count);
		}
	}
} 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 now =1;
		int count =0;
		while (now!=2) {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		}
		if (count>N) {
			System.out.println(-1);
		} else {
			System.out.println(count);
		}
	}
} 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 now =1;
		int count =0;
		while (now!=2) {
			if (count>N) {
				break;
			}
			now = a[now-1];
			count++;
		}
		if (count>N) {
			System.out.println(-1);
		} else {
			System.out.println(count);
		}
	}
}