Problem: Eugeny has n cards, each of them has exactly one integer written on it. Eugeny wants to exchange some cards with Nikolay so that the number of even integers on his cards would equal the number of odd integers, and that all these numbers would be distinct. 

Nikolay has m cards, distinct numbers from 1 to m are written on them, one per card. It means that Nikolay has exactly one card with number 1, exactly one card with number 2 and so on. 

A single exchange is a process in which Eugeny gives one card to Nikolay and takes another one from those Nikolay has. Your task is to find the minimum number of card exchanges and determine which cards Eugeny should exchange.

Input

The first line contains two integers n and m (2 ≤ n ≤ 2·105, 1 ≤ m ≤ 109) — the number of cards Eugeny has and the number of cards Nikolay has. It is guaranteed that n is even.

The second line contains a sequence of n positive integers a1, a2, ..., an (1 ≤ ai ≤ 109) — the numbers on Eugeny's cards.

Output

If there is no answer, print -1.

Otherwise, in the first line print the minimum number of exchanges. In the second line print n integers — Eugeny's cards after all the exchanges with Nikolay. The order of cards should coincide with the card's order in the input data. If the i-th card wasn't exchanged then the i-th number should coincide with the number from the input data. Otherwise, it is considered that this card was exchanged, and the i-th number should be equal to the number on the card it was exchanged to.

If there are multiple answers, it is allowed to print any of them.

Examples

Input

6 2
5 6 7 9 4 5


Output

1
5 6 7 9 4 2 


Input

8 6
7 7 7 7 8 8 8 8


Output

6
7 2 4 6 8 1 3 5 


Input

4 1
4 2 1 10


Output

-1

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.BitSet;
import java.util.Calendar;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.SortedSet;
import java.util.Stack;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;

/**
 * #
 * 
 * @author pttrung
 */
public class E_Round_386_Div2 {

	public static long MOD = 1000000007;

	public static void main(String[] args) throws FileNotFoundException {
		// PrintWriter out = new PrintWriter(new FileOutputStream(new File(
		// "output.txt")));
		PrintWriter out = new PrintWriter(System.out);
		Scanner in = new Scanner();
		int n = in.nextInt();
		int m = in.nextInt();
		int[] data = new int[n];
		for (int i = 0; i < n; i++) {
			data[i] = in.nextInt();
		}
		HashSet<Integer> odd = new HashSet<>();
		HashSet<Integer> even = new HashSet<>();
		int o = 0, e = 0;
		boolean ok = true;
		LinkedList<Integer> oddNorm = new LinkedList<>();
		LinkedList<Integer> oddRep = new LinkedList<>();
		LinkedList<Integer> evenRep = new LinkedList<>();
		LinkedList<Integer> evenNorm = new LinkedList<>();
		for (int i = 0; i < n; i++) {
			if (data[i] % 2 == 0) {
				if (!even.contains(data[i])) {
					even.add(data[i]);
					evenNorm.add(i);
				} else {

					evenRep.add(i);
				}

				e++;
			} else {
				if (!odd.contains(data[i])) {
					odd.add(data[i]);
					oddNorm.add(i);
				} else {

					oddRep.add(i);
				}
				o++;
			}
		}
		int startOdd = 1;
		int startEven = 2;
		int re = 0;
		// System.out.println(o + " " + e);
		if (o != e) {
			if (o > e) {
				for (int i = 0; i < (o - e) / 2; i++) {
					int index;
					if (!oddRep.isEmpty()) {
						index = oddRep.poll();
					} else {
						index = oddNorm.poll();
					}

					while (even.contains(startEven)) {
						startEven += 2;
					}
					if (startEven > m) {
						ok = false;
						break;
					}
					// System.out.println(index + " " + startEven);
					data[index] = startEven;
					startEven += 2;

					re++;
				}
			} else if (o < e) {
				for (int i = 0; i < (e - o) / 2; i++) {
					int index;
					if (!evenRep.isEmpty()) {
						index = evenRep.poll();
					} else {
						index = evenNorm.poll();
					}
					while (odd.contains(startOdd)) {
						startOdd += 2;
					}
					if (startOdd > m) {
						ok = false;
						break;
					}
					data[index] = startOdd;

					startOdd += 2;
					re++;
				}
			}
		}

		while (!oddRep.isEmpty() && ok) {
			int index = oddRep.poll();
			while (odd.contains(startOdd)) {
				startOdd += 2;
			}
			if (startOdd > m) {
				ok = false;
			}
			re++;
			data[index] = startOdd;
			startOdd += 2;
		}
		while (!evenRep.isEmpty() && ok) {
			int index = evenRep.poll();
			while (even.contains(startEven)) {
				startEven += 2;
			}
			if (startEven > m) {
				ok = false;
			}
			re++;
			data[index] = startEven;
			startEven += 2;
		}
		if (ok) {
			out.println(re);
			for (int i : data) {
				out.print(i + " ");
			}
		} else {
			out.println(-1);
		}
		out.close();
	}

	public static int[] KMP(String val) {
		int i = 0;
		int j = -1;
		int[] result = new int[val.length() + 1];
		result[0] = -1;
		while (i < val.length()) {
			while (j >= 0 && val.charAt(j) != val.charAt(i)) {
				j = result[j];
			}
			j++;
			i++;
			result[i] = j;
		}
		return result;

	}

	public static boolean nextPer(int[] data) {
		int i = data.length - 1;
		while (i > 0 && data[i] < data[i - 1]) {
			i--;
		}
		if (i == 0) {
			return false;
		}
		int j = data.length - 1;
		while (data[j] < data[i - 1]) {
			j--;
		}
		int temp = data[i - 1];
		data[i - 1] = data[j];
		data[j] = temp;
		Arrays.sort(data, i, data.length);
		return true;
	}

	public static int digit(long n) {
		int result = 0;
		while (n > 0) {
			n /= 10;
			result++;
		}
		return result;
	}

	public static double dist(long a, long b, long x, long y) {
		double val = (b - a) * (b - a) + (x - y) * (x - y);
		val = Math.sqrt(val);
		double other = x * x + a * a;
		other = Math.sqrt(other);
		return val + other;

	}

	public static class Point implements Comparable<Point> {

		int x, y;

		public Point(int start, int end) {
			this.x = start;
			this.y = end;
		}

		@Override
		public int hashCode() {
			int hash = 5;
			hash = 47 * hash + this.x;
			hash = 47 * hash + this.y;
			return hash;
		}

		@Override
		public boolean equals(Object obj) {
			if (obj == null) {
				return false;
			}
			if (getClass() != obj.getClass()) {
				return false;
			}
			final Point other = (Point) obj;
			if (this.x != other.x) {
				return false;
			}
			if (this.y != other.y) {
				return false;
			}
			return true;
		}

		@Override
		public int compareTo(Point o) {
			return Integer.compare(x, o.x);
		}
	}

	public static class FT {

		long[] data;

		FT(int n) {
			data = new long[n];
		}

		public void update(int index, long value) {
			while (index < data.length) {
				data[index] += value;
				index += (index & (-index));
			}
		}

		public long get(int index) {
			long result = 0;
			while (index > 0) {
				result += data[index];
				index -= (index & (-index));
			}
			return result;

		}
	}

	public static long gcd(long a, long b) {
		if (b == 0) {
			return a;
		}
		return gcd(b, a % b);
	}

	public static long pow(long a, long b) {
		if (b == 0) {
			return 1;
		}
		if (b == 1) {
			return a;
		}
		long val = pow(a, b / 2);
		if (b % 2 == 0) {
			return val * val % MOD;
		} else {
			return val * (val * a % MOD) % MOD;

		}
	}

	static class Scanner {

		BufferedReader br;
		StringTokenizer st;

		public Scanner() throws FileNotFoundException {
			// System.setOut(new PrintStream(new
			// BufferedOutputStream(System.out), true));
			br = new BufferedReader(new InputStreamReader(System.in));
			// br = new BufferedReader(new InputStreamReader(new
			// FileInputStream(new File("input.txt"))));
		}

		public String next() {

			while (st == null || !st.hasMoreTokens()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (Exception e) {
					throw new RuntimeException();
				}
			}
			return st.nextToken();
		}

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

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

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

		public String nextLine() {
			st = null;
			try {
				return br.readLine();
			} catch (Exception e) {
				throw new RuntimeException();
			}
		}

		public boolean endLine() {
			try {
				String next = br.readLine();
				while (next != null && next.trim().isEmpty()) {
					next = br.readLine();
				}
				if (next == null) {
					return true;
				}
				st = new StringTokenizer(next);
				return st.hasMoreTokens();
			} catch (Exception e) {
				throw new RuntimeException();
			}
		}
	}
}