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];
        int b = 1;
        int count = 0;
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        for (int i = 0; i < n; i++) {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        }
        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];
        int b = 1;
        int count = 0;
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        for (int i = 0; i < n; i++) {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        }
        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];
        int b = 1;
        int count = 0;
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        for (int i = 0; i < n; i++) {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        }
        System.out.println(-1);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] a = new int[n];
        int b = 1;
        int count = 0;
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        for (int i = 0; i < n; i++) {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        }
        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 int b = 1; b 1 int count = 0; count 0 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 for (int i = 0; i < n; i++) {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        } {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        } if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            } b == a[b - 1] b a[b - 1] a b - 1 b 1 {
                System.out.println(-1);
                System.exit(0);
            } System.out.println(-1) System.out.println System.out System System.out -1 1 System.exit(0) System.exit System 0 b = a[b - 1] b a[b - 1] a b - 1 b 1 count++ count if (b == 2) {
                System.out.println(count);
                System.exit(0);
            } b == 2 b 2 {
                System.out.println(count);
                System.exit(0);
            } System.out.println(count) System.out.println System.out System System.out count System.exit(0) System.exit System 0 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];
        int b = 1;
        int count = 0;
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        for (int i = 0; i < n; i++) {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        }
        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];
        int b = 1;
        int count = 0;
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        for (int i = 0; i < n; i++) {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        }
        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];
        int b = 1;
        int count = 0;
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        for (int i = 0; i < n; i++) {
            if (b == a[b - 1]) {
                System.out.println(-1);
                System.exit(0);
            }
            b = a[b - 1];
            count++;
            if (b == 2) {
                System.out.println(count);
                System.exit(0);
            }
        }
        System.out.println(-1);
    }
}
