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 next = 0;

    for (int i = 0; i < n; i++) {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    }

    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 now = 1;
    int next = 0;

    for (int i = 0; i < n; i++) {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    }

    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 now = 1;
    int next = 0;

    for (int i = 0; i < n; i++) {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    }

    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 now = 1;
    int next = 0;

    for (int i = 0; i < n; i++) {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    }

    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 now = 1; now 1 int next = 0; next 0 for (int i = 0; i < n; i++) {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    } {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    } next = a[now - 1] next a[now - 1] a now - 1 now 1 now = next now next if (next == 2) {
        System.out.println(i + 1);
        return;
      } next == 2 next 2 {
        System.out.println(i + 1);
        return;
      } System.out.println(i + 1) System.out.println System.out System System.out i + 1 i 1 return; 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 now = 1;
    int next = 0;

    for (int i = 0; i < n; i++) {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    }

    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 now = 1;
    int next = 0;

    for (int i = 0; i < n; i++) {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    }

    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 now = 1;
    int next = 0;

    for (int i = 0; i < n; i++) {
      next = a[now - 1];
      now = next;
      if (next == 2) {
        System.out.println(i + 1);
        return;
      }
    }

    System.out.println(-1);

  }
}