Problem: Welcome to another task about breaking the code lock! Explorers Whitfield and Martin came across an unusual safe, inside of which, according to rumors, there are untold riches, among which one can find the solution of the problem of discrete logarithm!

Of course, there is a code lock is installed on the safe. The lock has a screen that displays a string of n lowercase Latin letters. Initially, the screen displays string s. Whitfield and Martin found out that the safe will open when string t will be displayed on the screen.

The string on the screen can be changed using the operation «shift x». In order to apply this operation, explorers choose an integer x from 0 to n inclusive. After that, the current string p = αβ changes to βRα, where the length of β is x, and the length of α is n - x. In other words, the suffix of the length x of string p is reversed and moved to the beginning of the string. For example, after the operation «shift 4» the string «abcacb» will be changed with string «bcacab », since α = ab, β = cacb, βR = bcac.

Explorers are afraid that if they apply too many operations «shift», the lock will be locked forever. They ask you to find a way to get the string t on the screen, using no more than 6100 operations.

Input

The first line contains an integer n, the length of the strings s and t (1 ≤ n ≤ 2 000).

After that, there are two strings s and t, consisting of n lowercase Latin letters each.

Output

If it is impossible to get string t from string s using no more than 6100 operations «shift», print a single number  - 1.

Otherwise, in the first line output the number of operations k (0 ≤ k ≤ 6100). In the next line output k numbers xi corresponding to the operations «shift xi» (0 ≤ xi ≤ n) in the order in which they should be applied.

Examples

Input

6
abacbb
babcba


Output

4
6 3 2 3


Input

3
aba
bba


Output

-1

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;

import static java.lang.Math.*;
import static java.util.Arrays.*;
import static java.util.Collections.*;
import static java.util.Comparator.*;

public class Main {
    FastScanner in;
    PrintWriter out;

    boolean ok;
    int n, len;
    char[] s, t;
    ArrayList<Integer> ans;

    private void solve() throws IOException {
        n = in.nextInt();
        s = in.next().toCharArray();
        t = in.next().toCharArray();
        ans = new ArrayList<>();
        len = 0;
        ok = true;

        for (int i = 0, l = n / 2 - 1, r = n / 2 + 1; l >= 0 || r < n && ok; i++) {
            if (i == 0) {
                int pos = n - 1;
                while (pos >= 0 && s[pos] != t[n / 2])
                    pos--;
                if (pos < i) {
                    out.println(-1);
                    return;
                }
                if (n - 1 - pos > 0) {
                    ans.add(n - 1 - pos);
                    specRev(pos + 1);
                }
                len++;
            } else if (i % 2 == 1) {
                if (r + 1 < n) {
                    find2(t[r], t[r + 1]);
                    r += 2;
                } else if (r < n) {
                    find1(t[r]);
                    r++;
                } else
                    break;
            } else {
                if (l - 1 >= 0) {
                    find2(t[l], t[l - 1]);
                    l -= 2;
                } else if (l >= 0) {
                    find1(t[l]);
                    l--;
                } else
                    break;
            }
        }

        if (ok && !Arrays.equals(s, t))
            ans.add(n);

        if (ok) {
            out.println(ans.size());
            for (int i : ans)
                out.print(i + " ");
        } else
            out.println(-1);
    }

    private void find1(char x) {
        int pos = 0;
        while (pos < n - len && s[pos] != x)
            pos++;

        if (pos == n - len) {
            ok = false;
            return;
        }

        ans.add(n - 1 - pos);
        specRev(pos + 1);
        ans.add(1);
        specRev(n - 1);
        pos = len++;
        ans.add(n - 1 - pos);
        specRev(pos + 1);
    }

    private void find2(char x, char y) {
        int pos = 0;
        while (pos < n - len && s[pos] != x)
            pos++;

        if (pos == n - len) {
            ok = false;
            return;
        }

        ans.add(n - 1 - pos);
        specRev(pos + 1);
        ans.add(1);
        specRev(n - 1);
        len++;

        pos = n - 1;
        while (pos >= len && s[pos] != y)
            pos--;

        if (pos < len) {
            ok = false;
            return;
        }

        ans.add(n - pos);
        specRev(pos);
        ans.add(pos - len);
        specRev(n - pos + len);
        len++;
    }

    private void specRev(int pos) {
        StringBuilder sb = new StringBuilder();
        for (int i = n - 1; i >= pos; i--)
            sb.append(s[i]);
        for (int i = 0; i < pos; i++)
            sb.append(s[i]);
        s = sb.toString().toCharArray();
    }

    class FastScanner {
        StringTokenizer st;
        BufferedReader br;

        FastScanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        boolean hasNext() throws IOException {
            return br.ready() || (st != null && st.hasMoreTokens());
        }

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

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

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

        String nextLine() throws IOException {
            return br.readLine();
        }

        boolean hasNextLine() throws IOException {
            return br.ready();
        }
    }

    private void run() throws IOException {
        in = new FastScanner(System.in); // new FastScanner(new FileInputStream(".in"));
        out = new PrintWriter(System.out); // new PrintWriter(new FileOutputStream(".out"));

        solve();

        out.flush();
        out.close();
    }

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