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 + 1];
  for (int i = 0; i < n; i++)
    a[i] = sc.nextInt();
  int b = a[0];
  int ans = 1;
  while (b != 2) {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  }
  System.out.println(ans);
}} 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 + 1];
  for (int i = 0; i < n; i++)
    a[i] = sc.nextInt();
  int b = a[0];
  int ans = 1;
  while (b != 2) {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  }
  System.out.println(ans);
}} Main public static void main(String[] args) {
  Scanner sc = new Scanner(System.in);
  int n  = sc.nextInt();
  int[] a = new int[n + 1];
  for (int i = 0; i < n; i++)
    a[i] = sc.nextInt();
  int b = a[0];
  int ans = 1;
  while (b != 2) {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  }
  System.out.println(ans);
} main {
  Scanner sc = new Scanner(System.in);
  int n  = sc.nextInt();
  int[] a = new int[n + 1];
  for (int i = 0; i < n; i++)
    a[i] = sc.nextInt();
  int b = a[0];
  int ans = 1;
  while (b != 2) {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  }
  System.out.println(ans);
} 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 + 1]; a new int[n + 1] n + 1 n 1 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] a i sc.nextInt() sc.nextInt sc int b = a[0]; b a[0] a 0 int ans = 1; ans 1 while (b != 2) {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  } b != 2 b 2 {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  } b = a[b-1] b a[b-1] a b-1 b 1 ans++ ans if (ans > n) {
      ans = -1;
      break;
    } ans > n ans n {
      ans = -1;
      break;
    } ans = -1 ans -1 1 break; System.out.println(ans) System.out.println System.out System System.out ans 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 + 1];
  for (int i = 0; i < n; i++)
    a[i] = sc.nextInt();
  int b = a[0];
  int ans = 1;
  while (b != 2) {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  }
  System.out.println(ans);
}} public class Main {
public static void main(String[] args) {
  Scanner sc = new Scanner(System.in);
  int n  = sc.nextInt();
  int[] a = new int[n + 1];
  for (int i = 0; i < n; i++)
    a[i] = sc.nextInt();
  int b = a[0];
  int ans = 1;
  while (b != 2) {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  }
  System.out.println(ans);
}} 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 + 1];
  for (int i = 0; i < n; i++)
    a[i] = sc.nextInt();
  int b = a[0];
  int ans = 1;
  while (b != 2) {
    b = a[b-1];
    ans++;
    if (ans > n) {
      ans = -1;
      break;
    }
  }
  System.out.println(ans);
}}