You are given a chessboard of size 1 × n. It is guaranteed that n is even. The chessboard is painted like this: "BWBW...BW".

Some cells of the board are occupied by the chess pieces. Each cell contains no more than one chess piece. It is known that the total number of pieces equals to <image>.

In one step you can move one of the pieces one cell to the left or to the right. You cannot move pieces beyond the borders of the board. You also cannot move pieces to the cells that are already occupied.

Your task is to place all the pieces in the cells of the same color using the minimum number of moves (all the pieces must occupy only the black cells or only the white cells after all the moves are made).

Input

The first line of the input contains one integer n (2 ≤ n ≤ 100, n is even) — the size of the chessboard. 

The second line of the input contains <image> integer numbers <image> (1 ≤ pi ≤ n) — initial positions of the pieces. It is guaranteed that all the positions are distinct.

Output

Print one integer — the minimum number of moves you have to make to place all the pieces in the cells of the same color.

Examples

Input

6
1 2 6


Output

2


Input

10
1 2 3 4 5


Output

10

Note

In the first example the only possible strategy is to move the piece at the position 6 to the position 5 and move the piece at the position 2 to the position 3. Notice that if you decide to place the pieces in the white cells the minimum number of moves will be 3.

In the second example the possible strategy is to move <image> in 4 moves, then <image> in 3 moves, <image> in 2 moves and <image> in 1 move.
/**
 * Built using Sublime,Custom Python and Batch files
 * @author Siddhraj Sisodiya
 */

import java.io.*;
import java.util.*;
import java.math.*;

public class Main 
{
   public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        InputReader in = new InputReader(inputStream);
        Task solver = new Task(in);
        solver.solve();
    }

    static class Task
    {
        InputReader in;
        long m=1000000007;
        long temp=1;

        Task(InputReader in)
        {
            this.in=in;
        }

        public void solve()
        {
            int n=in.nextInt();
            int arr[]=in.nextIntArray(n/2);
            Arrays.sort(arr);
            int anse=0,anso=0;
            int temp=n;
            for(int i=n/2-1;i>=0;i--)
            {
                anse+=Math.abs(temp-arr[i]);
                temp-=2;
            }
            temp=n-1;
            for(int i=n/2-1;i>=0;i--)
            {
                anso+=Math.abs(temp-arr[i]);
                temp-=2;
            }
            if(anso<anse)
                System.out.println(anso);
            else
                System.out.println(anse);
        }
    }

    static class InputReader 
    {
        private boolean finished = false;

        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) 
        {
            this.stream = stream;
        }

        public int read() 
        {
            if (numChars == -1) 
            {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) 
            {
                curChar = 0;
                try 
                {
                    numChars = stream.read(buf);
                } catch (IOException e) 
                {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) 
                {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int peek() 
        {
            if (numChars == -1) 
            {
                return -1;
            }
            if (curChar >= numChars) 
            {
                curChar = 0;
                try 
                {
                    numChars = stream.read(buf);
                } catch (IOException e) 
                {
                    return -1;
                }
                if (numChars <= 0) 
                {
                    return -1;
                }
            }
            return buf[curChar];
        }

        public int nextInt() 
        {
            int c = read();
            while (isSpaceChar(c)) 
            {
                c = read();
            }
            int sgn = 1;
            if (c == '-') 
            {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do 
            {
                if (c < '0' || c > '9') 
                {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public long nextLong() 
        {
            int c = read();
            while (isSpaceChar(c)) 
            {
                c = read();
            }
            int sgn = 1;
            if (c == '-') 
            {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do 
            {
                if (c < '0' || c > '9') 
                {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public String nextString() 
        {
            int c = read();
            while (isSpaceChar(c)) 
            {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do 
            {
                if (Character.isValidCodePoint(c)) 
                {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) 
        {
            if (filter != null) 
            {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) 
        {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private String readLine0() 
        {
            StringBuilder buf = new StringBuilder();
            int c = read();
            while (c != '\n' && c != -1) 
            {
                if (c != '\r') 
                {
                    buf.appendCodePoint(c);
                }
                c = read();
            }
            return buf.toString();
        }

        public String readLine() 
        {
            String s = readLine0();
            while (s.trim().length() == 0) 
            {
                s = readLine0();
            }
            return s;
        }

        public String readLine(boolean ignoreEmptyLines) 
        {
            if (ignoreEmptyLines) 
            {
                return readLine();
            } else 
            {
                return readLine0();
            }
        }

        public BigInteger readBigInteger() 
        {
            try 
            {
                return new BigInteger(nextString());
            } catch (NumberFormatException e) 
            {
                throw new InputMismatchException();
            }
        }

        public char nextCharacter() 
        {
            int c = read();
            while (isSpaceChar(c)) 
            {
                c = read();
            }
            return (char) c;
        }

        public double nextDouble() 
        {
            int c = read();
            while (isSpaceChar(c)) 
            {
                c = read();
            }
            int sgn = 1;
            if (c == '-') 
            {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') 
            {
                if (c == 'e' || c == 'E') 
                {
                    return res * Math.pow(10, nextInt());
                }
                if (c < '0' || c > '9') 
                {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') 
            {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) 
                {
                    if (c == 'e' || c == 'E') 
                    {
                        return res * Math.pow(10, nextInt());
                    }
                    if (c < '0' || c > '9') 
                    {
                        throw new InputMismatchException();
                    }
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }

        public boolean isExhausted() 
        {
            int value;
            while (isSpaceChar(value = peek()) && value != -1) 
            {
                read();
            }
            return value == -1;
        }

        public String next() 
        {
            return nextString();
        }

        public SpaceCharFilter getFilter() 
        {
            return filter;
        }

        public void setFilter(SpaceCharFilter filter) 
        {
            this.filter = filter;
        }

        public interface SpaceCharFilter 
        {
            public boolean isSpaceChar(int ch);
        }
        public int[] nextIntArray(int n)
        {
            int[] array=new int[n];
            for(int i=0;i<n;++i)array[i]=nextInt();
            return array;
        }
        public int[] nextSortedIntArray(int n)
        {
            int array[]=nextIntArray(n);
            Arrays.sort(array);
            return array;
        }
        public int[] nextSumIntArray(int n)
        {
            int[] array=new int[n];
            array[0]=nextInt();
            for(int i=1;i<n;++i)array[i]=array[i-1]+nextInt();
            return array;
        }
        public long[] nextLongArray(int n)
        {
            long[] array=new long[n];
            for(int i=0;i<n;++i)array[i]=nextLong();
            return array;
        }
        public long[] nextSumLongArray(int n)
        {
            long[] array=new long[n];
            array[0]=nextInt();
            for(int i=1;i<n;++i)array[i]=array[i-1]+nextInt();
            return array;
        }
        public long[] nextSortedLongArray(int n)
        {
            long array[]=nextLongArray(n);
            Arrays.sort(array);
            return array;
        }
    }
}