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

import static java.util.Arrays.*;

public class _460 {
	private static final int mod = (int)1e9+7;

	final Random random = new Random(0);
	final IOFast io = new IOFast();

	/// MAIN CODE
	public void run() throws IOException {
//		int TEST_CASE = Integer.parseInt(new String(io.nextLine()).trim());
		int TEST_CASE = 1;
		while(TEST_CASE-- != 0) {
			int h = io.nextInt();
			int w = io.nextInt();
			int[] b = new int[h];
			for (int i = 0; i < h; i++)
				for (int j = 0; j < w; j++)
					b[i] |= io.nextInt() << j;
			int[][][] dp = new int[h+1][1<<w][1<<w];
			for (int[][] d : dp) for (int[] p : d) Arrays.fill(p, 1<<29);
			dp[0][0][0] = 0;
			
			int ans = 1<<29;
			for (int i = 0; i < h; i++) {
				for (int v1 = 0; v1 < 1 << w; v1++) {
					for (int v2 = 0; v2 < 1 << w; v2++) if (dp[i][v2][v1] != -1) {
//						dump(i, v1, v2, dp[i][v2][v1]);
						for (int v3 = 0; v3 < 1 << w; v3++) {
							
							if (i >= 1 && !zero(b[i-1], v1^v2^v3, w)) {
								continue;
							}
							
							dp[i+1][v3][v2] = Math.min(dp[i+1][v3][v2], dp[i][v2][v1] + Integer.bitCount(v3));
							if (i == h - 1 && zero(b[i], v2^v3, w)) {
								ans = Math.min(ans, dp[i+1][v3][v2]);
							}
						}
					}
				}
			}
			
			if (ans >= 1<<29) {
				io.out.println("Impossible");
			} else {
				io.out.println(ans);
			}
		}
	}
	
	boolean zero(int b, int v0, int w) {
		v0 = (v0 << 1 ^ v0 ^ v0 >> 1) & ((1<<w)-1);
		return (b ^ v0) == 0;
	}
	
	/// TEMPLATE
	static int gcd(int n, int r) { return r == 0 ? n : gcd(r, n%r); }
	static long gcd(long n, long r) { return r == 0 ? n : gcd(r, n%r); }
	
	static <T> void swap(T[] x, int i, int j) { T t = x[i]; x[i] = x[j]; x[j] = t; }
	static void swap(int[] x, int i, int j) { int t = x[i]; x[i] = x[j]; x[j] = t; }

	void printArrayLn(int[] xs) { for(int i = 0; i < xs.length; i++) io.out.print(xs[i] + (i==xs.length-1?"\n":" ")); }
	void printArrayLn(long[] xs) { for(int i = 0; i < xs.length; i++) io.out.print(xs[i] + (i==xs.length-1?"\n":" ")); }
	
	static void dump(Object... o) { System.err.println(Arrays.deepToString(o)); } 
	
	void main() throws IOException {
		//		IOFast.setFileIO("rle-size.in", "rle-size.out");
		try { run(); }
		catch (EndOfFileRuntimeException e) { }
		io.out.flush();
	}
	public static void main(String[] args) throws IOException { new _460().main(); }
	
	static class EndOfFileRuntimeException extends RuntimeException {
		private static final long serialVersionUID = -8565341110209207657L; }

	static
	public class IOFast {
		private InputStream in = System.in;
		private PrintWriter out = new PrintWriter(System.out);

		private static int pos, readLen;
		private static final byte[] buffer = new byte[1024 * 8];
		private static char[] str = new char[500*8*2];
		private static boolean[] isDigit = new boolean[256];
		private static boolean[] isSpace = new boolean[256];
		private static boolean[] isLineSep = new boolean[256];

		static { for(int i = 0; i < 10; i++) { isDigit['0' + i] = true; } isDigit['-'] = true; isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true; isLineSep['\r'] = isLineSep['\n'] = true; }
		public byte read() throws IOException { if(pos >= readLen) { pos = 0; readLen = in.read(buffer); if(readLen <= 0) { throw new EndOfFileRuntimeException(); } } return buffer[pos++]; }
		public int nextInt() throws IOException {
			byte first = (byte)nextChar();
			boolean minus = false;
			int res = 0;
			if (first == '-') {
				minus = true;
			} else {
				res = first - '0';
			}
			while (true) {
				byte b = read();
				if (isSpace[b]) break;
				res = res * 10 + b - '0';
			}
			return minus ? -res : res;
		}
		public long nextLong() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); int i = 0; long ret = 0; if(str[0] == '-') { i = 1; } for(; i < len; i++) ret = ret * 10 + str[i] - '0'; if(str[0] == '-') { ret = -ret; } return ret; }
		public char nextChar() throws IOException { while(true) { final int c = read(); if(!isSpace[c]) { return (char)c; } } }
		int reads(int len, boolean[] accept) throws IOException { try { while(true) { final int c = read(); if(accept[c]) { break; } if(str.length == len) { char[] rep = new char[str.length * 3 / 2]; System.arraycopy(str, 0, rep, 0, str.length); str = rep; } str[len++] = (char)c; } } catch(EndOfFileRuntimeException e) { ; } return len; }
		int reads(char[] cs, int len, boolean[] accept) throws IOException { try { while(true) { final int c = read(); if(accept[c]) { break; } cs[len++] = (char)c; } } catch(EndOfFileRuntimeException e) { ; } return len; }
		public char[] nextLine() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isLineSep); try { if(str[len-1] == '\r') { len--; read(); } } catch(EndOfFileRuntimeException e) { ; } return Arrays.copyOf(str, len); }
		public String nextString() throws IOException { return new String(next()); }
		public char[] next() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); return Arrays.copyOf(str, len); }
//		public int next(char[] cs) throws IOException { int len = 0; cs[len++] = nextChar(); len = reads(cs, len, isSpace); return len; }
//		public double nextDouble() throws IOException { return Double.parseDouble(nextString()); }
		public double nextDouble() throws IOException {
			double res = nextChar() - '0';
			while (true) {
				byte c = read();
				if (isSpace[c]) return res;
				if (c == '.') break;
				res = res * 10 + c - '0';
			}
			double d = 1;
			while (true) {
				byte c = read();
//				dump(c);
				if (!isDigit[c]) break;
				res = res * 10 + c - '0';
				d *= 10;
			}
//			dump(1);
			return res / d;
		}
		public long[] nextLongArray(final int n) throws IOException { final long[] res = new long[n]; for(int i = 0; i < n; i++) { res[i] = nextLong(); } return res; }
		public int[] nextIntArray(final int n) throws IOException { final int[] res = new int[n]; for(int i = 0; i < n; i++) { res[i] = nextInt(); } return res; }
		public int[][] nextIntArray2D(final int n, final int k) throws IOException { final int[][] res = new int[n][]; for(int i = 0; i < n; i++) { res[i] = nextIntArray(k); } return res; }
		public int[][] nextIntArray2DWithIndex(final int n, final int k) throws IOException { final int[][] res = new int[n][k+1]; for(int i = 0; i < n; i++) { for(int j = 0; j < k; j++) { res[i][j] = nextInt(); } res[i][k] = i; } return res; }
		public double[] nextDoubleArray(final int n) throws IOException { final double[] res = new double[n]; for(int i = 0; i < n; i++) { res[i] = nextDouble(); } return res; }
	}
}