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.
/*
 * 
 * @Author  Ajudiya_13(Bhargav Girdharbhai Ajudiya)
 * Dhirubhai Ambani Institute of Information And Communication Technology 
 * 
 */


import java.util.*;
import java.io.*;
import java.lang.*;

public class Code1
{
	
	public static void main(String[] args)
	{
		InputReader in = new InputReader(System.in);
		PrintWriter pw = new PrintWriter(System.out);
		
		int n = in.nextInt();
		int[] a = new int[n/2];
		a = in.nextIntArray(n/2);
		Arrays.sort(a);
		int[] b = new int[n/2];
		int[] c = new int[n/2];
		
		int j = 1;
		for(int i=0;i<n/2;i++)
		{
			b[i] = j;
			c[i] = j+1;
			j+=2;
		}
		
		int one = 0;
		int two = 0;
		for(int i=0;i<n/2;i++)
		{
			one+=Math.abs(b[i]-a[i]);
			two+=Math.abs(c[i]-a[i]);
		}
		pw.println(Math.min(one, two));
		pw.flush();
		pw.close();
	}
	
	static class InputReader 
	{
		 
		private final InputStream stream;
		private final byte[] buf = new byte[8192];
		private int curChar, snumChars;
		private SpaceCharFilter filter;
 
		public InputReader(InputStream stream) 
		{
			this.stream = stream;
		}
 
		public int snext() 
		{
			if (snumChars == -1)
				throw new InputMismatchException();
			if (curChar >= snumChars) 
			{
				curChar = 0;
				try 
				{
					snumChars = stream.read(buf);
				} 
				catch (IOException e) 
				{
					throw new InputMismatchException();
				}
				if (snumChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}
 
		public int nextInt() 
	    {
			int c = snext();
			while (isSpaceChar(c)) 
			{
				c = snext();
			}
			int sgn = 1;
			if (c == '-')
		    {
				sgn = -1;
				c = snext();
			}
			int res = 0;
			do 
			{
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = snext();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
 
		public long nextLong()
	    {
			int c = snext();
			while (isSpaceChar(c)) 
			{
				c = snext();
			}
			int sgn = 1;
			if (c == '-') 
			{
				sgn = -1;
				c = snext();
			}
			long res = 0;
			do 
			{
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = snext();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
 
		public int[] nextIntArray(int n) 
		{
			int a[] = new int[n];
			for (int i = 0; i < n; i++) 
			{
				a[i] = nextInt();
			}
			return a;
		}
 
		public String readString()
	    {
			int c = snext();
			while (isSpaceChar(c)) 
			{
				c = snext();
			}
			StringBuilder res = new StringBuilder();
			do 
			{
				res.appendCodePoint(c);
				c = snext();
			} while (!isSpaceChar(c));
			return res.toString();
		}
 
		public String nextLine() 
		{
			int c = snext();
			while (isSpaceChar(c))
				c = snext();
			StringBuilder res = new StringBuilder();
			do 
			{
				res.appendCodePoint(c);
				c = snext();
			} while (!isEndOfLine(c));
			return res.toString();
		}
 
		public boolean isSpaceChar(int c) 
		{
			if (filter != null)
				return filter.isSpaceChar(c);
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}
 
		private boolean isEndOfLine(int c) 
		{
			return c == '\n' || c == '\r' || c == -1;
		}
 
		public interface SpaceCharFilter
	    {
			public boolean isSpaceChar(int ch);
		}
	}
	
	public static long mod = 1000000007;
	public static int d;
	public static int p;
	public static int q;
	
	public static int[] suffle(int[] a,Random gen)
	{
		int n = a.length;
		for(int i=0;i<n;i++)
		{
			int ind = gen.nextInt(n-i)+i;
			int temp = a[ind];
			a[ind] = a[i];
			a[i] = temp;
		}
		return a;
	}
	
	public static void swap(int a, int b){
		int temp = a;
		a = b;
		b = temp;
	}
	
	public static HashSet<Integer> primeFactorization(int n)
	{
		HashSet<Integer> a =new HashSet<Integer>();
		for(int i=2;i*i<=n;i++)
		{
			while(n%i==0)
			{
				a.add(i);
				n/=i;
			}
		}
		if(n!=1)
			a.add(n);
		return a;
	}
	
	public static void sieve(boolean[] isPrime,int n)
	{
		for(int i=1;i<n;i++)
			isPrime[i] = true;
		
		isPrime[0] = false;
		isPrime[1] = false;
		
		for(int i=2;i*i<n;i++)
		{
			if(isPrime[i] == true)
			{
				for(int j=(2*i);j<n;j+=i)
					isPrime[j] = false;
			}
		}
	}
	
	public static int GCD(int a,int b)
	{
		if(b==0)
			return a;
		else
			return GCD(b,a%b);
	}
	
	public static long GCD(long a,long b)
	{
		if(b==0)
			return a;
		else
			return GCD(b,a%b);
	}
	
	public static void extendedEuclid(int A,int B)
	{
		if(B==0)
		{
			d = A;
			p = 1 ;
			q = 0;
		}
		else
		{
			extendedEuclid(B, A%B);
			int temp = p;
			p = q;
			q = temp - (A/B)*q;
		}
	}
	
	public static long LCM(long a,long b)
	{
		return (a*b)/GCD(a,b);
	}
	
	public static int LCM(int a,int b)
	{
		return (a*b)/GCD(a,b);
	}
	
	public static int binaryExponentiation(int x,int n)
	{
	    int result=1;
	    while(n>0)
	    {
	        if(n % 2 ==1)
	            result=result * x;
	        x=x*x;
	        n=n/2;
	    }
	    return result;
	}
	
	public static long binaryExponentiation(long x,long n)
	{
	    long result=1;
	    while(n>0)
	    {
	        if(n % 2 ==1)
	            result=result * x;
	        x=x*x;
	        n=n/2;
	    }
	    return result;
	}
	
	public static int modularExponentiation(int x,int n,int M)
	{
	    int result=1;
	    while(n>0)
	    {
	        if(n % 2 ==1)
	            result=(result * x)%M;
	        x=(x*x)%M;
	        n=n/2;
	    }
	    return result;
	}
	
	public static long modularExponentiation(long x,long n,long M)
	{
	    long result=1;
	    while(n>0)
	    {
	        if(n % 2 ==1)
	            result=(result * x)%M;
	        x=(x*x)%M;
	        n=n/2;
	    }
	    return result;
	}
	
	public static int modInverse(int A,int M)
	{
	    return modularExponentiation(A,M-2,M);
	}
	
	public static long modInverse(long A,long M)
	{
	    return modularExponentiation(A,M-2,M);
	}
	
	public static boolean isPrime(int n)
	{
	    
	    if (n <= 1)  return false;
	    if (n <= 3)  return true;
	    
	    if (n%2 == 0 || n%3 == 0) 
	    	return false;
	 
	    for (int i=5; i*i<=n; i=i+6)
	    {
	        if (n%i == 0 || n%(i+2) == 0)
	           return false;
	    }
	    
	    return true;
	}
	
	static class pair implements Comparable<pair>
	{
		Integer x, y;
		pair(int x,int y)
		{
			this.x=x;
			this.y=y;
		}
		
		public int compareTo(pair o) {
			int result = x.compareTo(o.x);
			if(result==0)
				result = y.compareTo(o.y);
			
			return result;
		}  
		
		public String toString()
		{
			return x+" "+y;
		}
		
		public boolean equals(Object o)
		{
			if (o instanceof pair)
		    {
				pair p = (pair)o;
				return p.x == x && p.y == y ;
			}
			return false;
		}
		
		public int hashCode()
		{
			return new Long(x).hashCode()*31 + new Long(y).hashCode();
		}
	}
}