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];
        boolean[] pushed = new boolean[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            pushed[i] = false;
        }

        long count = 0;
        int i = 0;
        while (true) {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        }
        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];
        boolean[] pushed = new boolean[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            pushed[i] = false;
        }

        long count = 0;
        int i = 0;
        while (true) {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        }
        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];
        boolean[] pushed = new boolean[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            pushed[i] = false;
        }

        long count = 0;
        int i = 0;
        while (true) {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        }
        System.out.println(count);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] a = new int[n];
        boolean[] pushed = new boolean[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            pushed[i] = false;
        }

        long count = 0;
        int i = 0;
        while (true) {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        }
        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 boolean[] pushed = new boolean[n]; pushed new boolean[n] n for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            pushed[i] = false;
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            a[i] = sc.nextInt();
            pushed[i] = false;
        } {
            a[i] = sc.nextInt();
            pushed[i] = false;
        } a[i] = sc.nextInt() a[i] a i sc.nextInt() sc.nextInt sc pushed[i] = false pushed[i] pushed i false long count = 0; count 0 int i = 0; i 0 while (true) {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        } true {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        } if (pushed[i]) {
                System.out.println(-1);
                return;
            } pushed[i] pushed i {
                System.out.println(-1);
                return;
            } System.out.println(-1) System.out.println System.out System System.out -1 1 return; count++ count if (a[i] == 2) {
                break;
            } a[i] == 2 a[i] a i 2 {
                break;
            } break; pushed[i] = true pushed[i] pushed i true i = a[i] - 1 i a[i] - 1 a[i] a i 1 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];
        boolean[] pushed = new boolean[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            pushed[i] = false;
        }

        long count = 0;
        int i = 0;
        while (true) {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        }
        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];
        boolean[] pushed = new boolean[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            pushed[i] = false;
        }

        long count = 0;
        int i = 0;
        while (true) {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        }
        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];
        boolean[] pushed = new boolean[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
            pushed[i] = false;
        }

        long count = 0;
        int i = 0;
        while (true) {
            if (pushed[i]) {
                System.out.println(-1);
                return;
            }
            count++;
            if (a[i] == 2) {
                break;
            }
            pushed[i] = true;
            i = a[i] - 1;
        }
        System.out.println(count);
    }

}
