import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    int n;
    int[] as;

    public static void main(String args[]) {
        new Main().run();
    }

    void run() {
        FastReader sc = new FastReader();
        n = sc.nextInt();
        as = new int[n];
        for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt() - 1;
        }
        solve();
    }

    void solve() {
        boolean[] used = new boolean[n];
        int current = 0;
        int count = 0;
        while (true) {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        }
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main {
    int n;
    int[] as;

    public static void main(String args[]) {
        new Main().run();
    }

    void run() {
        FastReader sc = new FastReader();
        n = sc.nextInt();
        as = new int[n];
        for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt() - 1;
        }
        solve();
    }

    void solve() {
        boolean[] used = new boolean[n];
        int current = 0;
        int count = 0;
        while (true) {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        }
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
} Main int n; n int[] as; as public static void main(String args[]) {
        new Main().run();
    } main {
        new Main().run();
    } new Main().run() new Main().run new Main() String args[] args void run() {
        FastReader sc = new FastReader();
        n = sc.nextInt();
        as = new int[n];
        for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt() - 1;
        }
        solve();
    } run {
        FastReader sc = new FastReader();
        n = sc.nextInt();
        as = new int[n];
        for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt() - 1;
        }
        solve();
    } FastReader sc = new FastReader(); sc new FastReader() n = sc.nextInt() n sc.nextInt() sc.nextInt sc as = new int[n] as new int[n] n for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt() - 1;
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            as[i] = sc.nextInt() - 1;
        } {
            as[i] = sc.nextInt() - 1;
        } as[i] = sc.nextInt() - 1 as[i] as i sc.nextInt() - 1 sc.nextInt() sc.nextInt sc 1 solve() solve void solve() {
        boolean[] used = new boolean[n];
        int current = 0;
        int count = 0;
        while (true) {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        }
    } solve {
        boolean[] used = new boolean[n];
        int current = 0;
        int count = 0;
        while (true) {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        }
    } boolean[] used = new boolean[n]; used new boolean[n] n int current = 0; current 0 int count = 0; count 0 while (true) {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        } true {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        } if (current == 1) {
                System.out.println(count);
                return;
            } current == 1 current 1 {
                System.out.println(count);
                return;
            } System.out.println(count) System.out.println System.out System System.out count return; if (used[current]) {
                System.out.println(-1);
                return;
            } used[current] used current {
                System.out.println(-1);
                return;
            } System.out.println(-1) System.out.println System.out System System.out -1 1 return; used[current] = true used[current] used current true count++ count current = as[current] current as[current] as current static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    } FastReader BufferedReader br; br StringTokenizer st; st public FastReader() {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        } FastReader {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        } br = new BufferedReader(new
                    InputStreamReader(System.in)) br new BufferedReader(new
                    InputStreamReader(System.in)) String next() {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        } next {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        } while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            } st == null || !st.hasMoreElements() st == null st null !st.hasMoreElements() st.hasMoreElements() st.hasMoreElements st {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            } try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                } catch (IOException e)
                {
                    e.printStackTrace();
                } IOException e {
                    e.printStackTrace();
                } e.printStackTrace() e.printStackTrace e {
                    st = new StringTokenizer(br.readLine());
                } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st int nextInt()
        {
            return Integer.parseInt(next());
        } nextInt {
            return Integer.parseInt(next());
        } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next long nextLong()
        {
            return Long.parseLong(next());
        } nextLong {
            return Long.parseLong(next());
        } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next double nextDouble()
        {
            return Double.parseDouble(next());
        } nextDouble {
            return Double.parseDouble(next());
        } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next String nextLine() {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        } nextLine {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        } String str = ""; str "" try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            } catch (IOException e)
            {
                e.printStackTrace();
            } IOException e {
                e.printStackTrace();
            } e.printStackTrace() e.printStackTrace e {
                str = br.readLine();
            } str = br.readLine() str br.readLine() br.readLine br return str; str public class Main {
    int n;
    int[] as;

    public static void main(String args[]) {
        new Main().run();
    }

    void run() {
        FastReader sc = new FastReader();
        n = sc.nextInt();
        as = new int[n];
        for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt() - 1;
        }
        solve();
    }

    void solve() {
        boolean[] used = new boolean[n];
        int current = 0;
        int count = 0;
        while (true) {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        }
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
} public class Main {
    int n;
    int[] as;

    public static void main(String args[]) {
        new Main().run();
    }

    void run() {
        FastReader sc = new FastReader();
        n = sc.nextInt();
        as = new int[n];
        for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt() - 1;
        }
        solve();
    }

    void solve() {
        boolean[] used = new boolean[n];
        int current = 0;
        int count = 0;
        while (true) {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        }
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    int n;
    int[] as;

    public static void main(String args[]) {
        new Main().run();
    }

    void run() {
        FastReader sc = new FastReader();
        n = sc.nextInt();
        as = new int[n];
        for (int i = 0; i < n; i++) {
            as[i] = sc.nextInt() - 1;
        }
        solve();
    }

    void solve() {
        boolean[] used = new boolean[n];
        int current = 0;
        int count = 0;
        while (true) {
            if (current == 1) {
                System.out.println(count);
                return;
            }
            if (used[current]) {
                System.out.println(-1);
                return;
            }
            used[current] = true;
            count++;
            current = as[current];
        }
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

        long nextLong()
        {
            return Long.parseLong(next());
        }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
}
