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


public class Main_yukicoder460 {

	private static Scanner sc;
	private static Printer pr;

	private static void solve() {
		int m = sc.nextInt();
		int n = sc.nextInt();

		int[][] a = new int[m][n];
		for (int i = 0; i < m; i++) {
			for (int j = 0; j < n; j++) {
				a[i][j] = sc.nextInt();
			}
		}

		Map<Long, Integer> hm = new HashMap<>();
		Map<Long, Integer> hm2 = new HashMap<>();
		{
			int[] mask = new int[n];
			for (int i = 0; i < n; i++) {
				for (int j = 0; j < n; j++) {
					if (Math.abs(i - j) <= 1) {
						mask[i] |= 0x1 << (n - 1 - j);
					}
				}
			}

			for (int i = 0; i < 0x1 << n; i++) {
				long ans = 0;
				for (int j = 0; j < n; j++) {
					if ((i & 0x1 << j) != 0) {
						ans ^= mask[j];
					}
				}

				if (hm.containsKey(ans)) {
					if (hm.get(ans) > Integer.bitCount(i)) {
						hm.put(ans, Integer.bitCount(i));
						hm2.put(ans, i);
					}
				} else {
					hm.put(ans, Integer.bitCount(i));
					hm2.put(ans, i);
				}
			}
		}

		long[][] conv = new long[m][n];
		int[][] tmp = new int[m][n];
		for (int i = 0; i < m; i++) {
			for (int j = 0; j < n; j++) {
				for (int ii = 0; ii < m; ii++) {
					for (int jj = 0; jj < n; jj++) {
						if (Math.abs(ii - i) <= 1 && Math.abs(jj - j) <= 1) {
							tmp[ii][jj] = 1;
						} else {
							tmp[ii][jj] = 0;
						}
					}
				}
				conv[i][j] = enc(tmp);
			}
		}

		long st = enc(a);

		int min = Integer.MAX_VALUE;
		for (int i = 0; i < 0x1 << n; i++) {
			long ans = st;
			for (int j = 0; j < n; j++) {
				if ((i & 0x1 << j) != 0) {
					ans ^= conv[0][j];
				}
			}

			int cnt = Integer.bitCount(i);
			for (int j = 1; j < m; j++) {
				long line = getLine(ans, j - 1, m, n);
				cnt += hm.get(line);
				int mask = hm2.get(line);
				for (int k = 0; k < n; k++) {
					if ((mask & 0x1 << k) != 0) {
						ans ^= conv[j][k];
					}
				}
			}

			if (getLine(ans, m - 1, m, n) == 0) {
				min = Math.min(min, cnt);
			}
		}

		if (min == Integer.MAX_VALUE) {
			pr.println("Impossible");
		} else {
			pr.println(min);
		}
	}

	private static long enc(int[][] a) {
		int m = a.length;
		int n = a[0].length;

		long tmp = 0;
		for (int i = 0; i < m; i++) {
			tmp <<= 8;
			for (int j = 0; j < n; j++) {
				if (a[i][j] == 1) {
					tmp |= 0x1 << n - 1 - j;
				}
			}
		}

		return tmp;
	}

	// k行目を取り出す
	private static long getLine(long a, int k, int m, int n) {
		return (a >> 8 * (m - 1 - k)) & 0xff;
	}

	// ---------------------------------------------------
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		pr = new Printer(System.out);

		solve();

		pr.close();
		sc.close();
	}

	private static class Printer extends PrintWriter {
		Printer(PrintStream out) {
			super(out);
		}
	}
}