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];
    for(int i = 0;i<n;i++){
      a[i] = sc.nextInt();
    }
    int ans = 0,times = 0,now = 1;
    for(int i = 0;i<n;i++){
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    }
    if(ans == 1){
      System.out.println(times);
    }else{
      System.out.println(-1);
    }
  }
} 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];
    for(int i = 0;i<n;i++){
      a[i] = sc.nextInt();
    }
    int ans = 0,times = 0,now = 1;
    for(int i = 0;i<n;i++){
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    }
    if(ans == 1){
      System.out.println(times);
    }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 ans = 0,times = 0,now = 1;
    for(int i = 0;i<n;i++){
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    }
    if(ans == 1){
      System.out.println(times);
    }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 ans = 0,times = 0,now = 1;
    for(int i = 0;i<n;i++){
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    }
    if(ans == 1){
      System.out.println(times);
    }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 ans = 0 ans 0 times = 0 times 0 now = 1; now 1 for(int i = 0;i<n;i++){
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    } int i = 0; int i = 0; i 0 i<n i n i++ i++ i {
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    } {
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    } times++ times now-- now now = a[now] now a[now] a now if(now == 2){
        ans = 1;
        break;
      } now == 2 now 2 {
        ans = 1;
        break;
      } ans = 1 ans 1 break; if(ans == 1){
      System.out.println(times);
    }else{
      System.out.println(-1);
    } ans == 1 ans 1 {
      System.out.println(times);
    } System.out.println(times) System.out.println System.out System System.out times {
      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 ans = 0,times = 0,now = 1;
    for(int i = 0;i<n;i++){
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    }
    if(ans == 1){
      System.out.println(times);
    }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 ans = 0,times = 0,now = 1;
    for(int i = 0;i<n;i++){
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    }
    if(ans == 1){
      System.out.println(times);
    }else{
      System.out.println(-1);
    }
  }
} 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];
    for(int i = 0;i<n;i++){
      a[i] = sc.nextInt();
    }
    int ans = 0,times = 0,now = 1;
    for(int i = 0;i<n;i++){
      times++;
      now--;
      now = a[now];
      if(now == 2){
        ans = 1;
        break;
      }
    }
    if(ans == 1){
      System.out.println(times);
    }else{
      System.out.println(-1);
    }
  }
}
