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

import static java.lang.Integer.compare;
import static java.lang.Math.*;
import static java.lang.System.in;
import static java.lang.System.out;
import static java.util.Arrays.deepToString;

/*
 *
 *21/5/18
 *8:08 PM
 *remedy441
 *
 */
public class CF985 {
    public static int mod = (int) (1e9 + 7);
    public static InputReader in;
    public static PrintWriter out;


    public static void solve() throws FileNotFoundException {

    	in = new InputReader(System.in);
    	out = new PrintWriter(System.out);
    	int n = in.ni();
    	int ar[] = in.nIArr(n/2);
    	Arrays.sort(ar);
    	int ans1 = 0;
    	int ans2 = 0;
    	int e = 2;
    	int o = 1;
    	for(int i=0;i<n/2;i++){
    	    ans1+=Math.abs(ar[i]-o);
            ans2+=Math.abs(ar[i]-e);
            e+=2;
            o+=2;
        }
        out.println(Math.min(ans1,ans2));

    	out.close();
    }
    public static void main(String[] args) {
    	new Thread(null, new Runnable() {
    		public void run() {
    			try {
    				solve();
    			} catch (Exception e) {
    				e.printStackTrace();
    			}
    		}
    	}, "1", 1 << 26).start();
    }

    static class Pair implements Comparable<Pair> {

    	int x, y, i;

    	Pair(int x, int y, int i) {
    		this.x = x;
    		this.y = y;
    		this.i = i;
    	}

    	Pair(int x, int y) {
    		this.x = x;
    		this.y = y;
    	}

    	public int compareTo(Pair o) {
    		if (this.x != o.x)
    			return compare(this.x, o.x);
    		else
    			return compare(this.y, o.y);
    		//return 0;
    	}

    	public boolean equals(Object o) {
    		if (o instanceof Pair) {
    			Pair p = (Pair) o;
    			return p.x == x && p.y == y && p.i == i;
    		}
    		return false;
    	}

    	public int hashCode() {
    		return new Integer(x).hashCode() * 31 + new Integer(y).hashCode() + new Integer(i).hashCode() * 37;
    	}

    }

    public static long add(long a, long b) {
    	long x = (a + b);
    	while (x >= mod)
    		x -= mod;
    	return x;
    }

    public static long sub(long a, long b) {
    	long x = (a - b);
    	while (x < 0)
    		x += mod;
    	return x;
    }

    public static long mul(long a, long b) {
    	long x = (a * b);
    	while (x >= mod)
    		x -= mod;
    	return x;
    }

    public static boolean isPal(String s) {
    	for (int i = 0, j = s.length() - 1; i <= j; i++, j--) {
    		if (s.charAt(i) != s.charAt(j))
    			return false;
    	}
    	return true;
    }

    public static String rev(String s) {
    	StringBuilder sb = new StringBuilder(s);
    	sb.reverse();
    	return sb.toString();
    }

    public static long gcd(long x, long y) {
    	if (x % y == 0)
    		return y;
    	else
    		return gcd(y, x % y);
    }

    public static int gcd(int x, int y) {
    	if (x % y == 0)
    		return y;
    	else
    		return gcd(y, x % y);
    }

    static int modInverse(int a, int m) {
    	int m0 = m, t, q;
    	int x0 = 0, x1 = 1;
    	if (m == 1)
    		return 0;
    	while (a > 1) {
    		// q is quotient
    		q = a / m;
    		t = m;
    		// m is remainder now, process same as
    		// Euclid's algo
    		m = a % m;
    		a = t;
    		t = x0;
    		x0 = x1 - q * x0;
    		x1 = t;
    	}
    	// Make x1 positive
    	if (x1 < 0)
    		x1 += m0;
    	return x1;
    }

    public static long gcdExtended(long a, long b, long[] x) {

    	if (a == 0) {
    		x[0] = 0;
    		x[1] = 1;
    		return b;
    	}
    	long[] y = new long[2];
    	long gcd = gcdExtended(b % a, a, y);

    	x[0] = y[1] - (b / a) * y[0];
    	x[1] = y[0];

    	return gcd;
    }

    public static long mulmod(long a, long b, long m) {
    	if (m <= 1000000009)
    		return a * b % m;

    	long res = 0;
    	while (a > 0) {
    		if ((a & 1) != 0) {
    			res += b;
    			if (res >= m)
    				res -= m;
    		}
    		a >>= 1;
    		b <<= 1;
    		if (b >= m)
    			b -= m;
    	}
    	return res;
    }

    public static int abs(int a, int b) {
    	return (int) Math.abs(a - b);
    }

    public static long abs(long a, long b) {
    	return (long) Math.abs(a - b);
    }

    public static int max(int a, int b) {
    	if (a > b)
    		return a;
    	else
    		return b;
    }

    public static int min(int a, int b) {
    	if (a > b)
    		return b;
    	else
    		return a;
    }

    public static long max(long a, long b) {
    	if (a > b)
    		return a;
    	else
    		return b;
    }

    public static long min(long a, long b) {
    	if (a > b)
    		return b;
    	else
    		return a;
    }

    public static long pow(long n, long p, long m) {
    	long result = 1;
    	if (p == 0)
    		return 1;
    	if (p == 1)
    		return n;
    	while (p != 0) {
    		if (p % 2 == 1)
    			result *= n;
    		if (result >= m)
    			result %= m;
    		p >>= 1;
    		n *= n;
    		if (n >= m)
    			n %= m;
    	}
    	return result;
    }

    public static long pow(long n, long p) {
    	long result = 1;
    	if (p == 0)
    		return 1;
    	if (p == 1)
    		return n;
    	while (p != 0) {
    		if (p % 2 == 1)
    			result *= n;
    		p >>= 1;
    		n *= n;
    	}
    	return result;
    }

    public static void debug(Object... o) {
    	System.out.println(deepToString(o));
    }

    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 ni() {
    		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 nl() {
    		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[] nIArr(int n) {
    		int a[] = new int[n];
    		for (int i = 0; i < n; i++) {
    			a[i] = ni();
    		}
    		return a;
    	}

    	public long[] nLArr(int n) {
    		long a[] = new long[n];
    		for (int i = 0; i < n; i++) {
    			a[i] = nl();
    		}
    		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);
    	}

    }

}
