import 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 = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    }
    int light = 1;
    int[] used = new int[N + 1];
    int count = 0;
    while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      count++;
    }
  }
} import java.util.*; util.* java 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 = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    }
    int light = 1;
    int[] used = new int[N + 1];
    int count = 0;
    while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      count++;
    }
  }
} 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 = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    }
    int light = 1;
    int[] used = new int[N + 1];
    int count = 0;
    while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      count++;
    }
  } main {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] a = new int[N + 1];
    for (int i = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    }
    int light = 1;
    int[] used = new int[N + 1];
    int count = 0;
    while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      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 + 1]; a new int[N + 1] N + 1 N 1 for (int i = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    } int i = 1; int i = 1; i 1 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 light = 1; light 1 int[] used = new int[N + 1]; used new int[N + 1] N + 1 N 1 int count = 0; count 0 while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      count++;
    } true {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      count++;
    } if (used[light] > 0) {
        System.out.println(-1);
        return;
      } used[light] > 0 used[light] used light 0 {
        System.out.println(-1);
        return;
      } System.out.println(-1) System.out.println System.out System System.out -1 1 return; if (light == 2) {
        System.out.println(count);
        return;
      } light == 2 light 2 {
        System.out.println(count);
        return;
      } System.out.println(count) System.out.println System.out System System.out count return; used[light] = 1 used[light] used light 1 light = a[light] light a[light] a light count++ 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 + 1];
    for (int i = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    }
    int light = 1;
    int[] used = new int[N + 1];
    int count = 0;
    while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      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 + 1];
    for (int i = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    }
    int light = 1;
    int[] used = new int[N + 1];
    int count = 0;
    while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      count++;
    }
  }
} Main
import 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 = 1; i <= N; i++) {
      a[i] = sc.nextInt();
    }
    int light = 1;
    int[] used = new int[N + 1];
    int count = 0;
    while (true) {
      if (used[light] > 0) {
        System.out.println(-1);
        return;
      }
      if (light == 2) {
        System.out.println(count);
        return;
      }
      used[light] = 1;
      light = a[light];
      count++;
    }
  }
}