package yukicoder;

import java.util.*;

public class Q460 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		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();
			}
		}

		int[][] mx = new int[M * N][M * N];
		int[] v = new int[M * N];
		for (int i = 0; i < M; ++i) {
			for (int j = 0; j < N; ++j) {
				v[i * N + j] = a[i][j];
			}
		}

		for (int i = 0; i < M; ++i) {
			for (int j = 0; j < N; ++j) {
				for (int dx = -1; dx <= 1; ++dx) {
					for (int dy = -1; dy <= 1; ++dy) {
						int nx = j + dx;
						int ny = i + dy;
						if (nx < 0 || ny < 0 || nx >= N || ny >= M)
							continue;
						mx[i * N + j][ny * N + nx] = 1;
					}
				}
			}
		}

		for (int i = 0; i < M * N; ++i) {
			int j = i;
			while (j < M * N && mx[j][i] == 0) {
				++j;
			}
			if (j == M * N)
				continue;
			if (i != j) {
				for (int k = 0; k < N * M; ++k) {
					int d = mx[i][k];
					mx[i][k] = mx[j][k];
					mx[j][k] = d;
				}
				int d = v[i];
				v[i] = v[j];
				v[j] = d;

			}
			for (int k = 0; k < M * N; ++k) {
				if (k == i)
					continue;
				if (mx[k][i] == 1) {
					for (int l = 0; l < M * N; ++l) {
						mx[k][l] = (mx[k][l] + mx[i][l]) % 2;
					}
					v[k] = (v[k] + v[i]) % 2;
				}
			}
		}

		ArrayList<Integer>[] to = new ArrayList[N * M];
		for (int i = 0; i < N * M; ++i) {
			to[i] = new ArrayList<>();
		}
		int c = 0;
		ArrayList<Integer> pending = new ArrayList<>();
		for (int i = N * M - 1; i >= 0; --i) {
			for (int k = 0; k < N * M; ++k) {
				if (mx[i][k] == 1) {
					to[k].add(i);
				}
			}
			ArrayDeque<Integer> tmp = new ArrayDeque<>();
			for (int k = i + 1; k < N * M; ++k) {
				if (mx[i][k] == 1) {
					tmp.add(k);
				}
			}
			if (tmp.size() > 0) {
				pending.addAll(tmp);
				continue;
			}
			if (tmp.size() == 0 && mx[i][i] == 1 && v[i] == 1) {
				++c;
				for (int k = 0; k <= i; ++k) {
					if (mx[k][i] == 1) {
						v[k] = v[k] ^ 1;
					}
				}
			} else if (v[i] == 1 && mx[i][i] == 0 && tmp.size() == 0) {
				if (mx[i][i] != 1) {
					System.out.println("Impossible");
					return;
				}
			}
		}
		int ans = Integer.MAX_VALUE;
		Collections.sort(pending);
		for (int i = 0; i < pending.size(); ++i) {
			while (i + 1 < pending.size() && pending.get(i) == pending.get(i + 1)) {
				pending.remove(i + 1);
			}
		}
		out: for (int i = 0; i < (1 << pending.size()); ++i) {
			int[] nv = Arrays.copyOf(v, v.length);
			int used = 0;
			for (int k = 0; k < pending.size(); ++k) {
				if ((i & (1 << k)) > 0) {
					++used;
					for (int t : to[pending.get(k)]) {
						nv[t] ^= 1;
					}
				}
			}
			for (int j = 0; j < N * M; ++j) {
				if (nv[j] == 1) {
					if (mx[j][j] == 0)
						continue out;
					else {
						++used;
						nv[j] ^= 1;
					}

				}
			}
			ans = Math.min(ans, c + used);
		}
		System.out.println(ans);
	}

	static void show(int[][] mx, int[] v, int M, int N) {
		for (int i = 0; i < M * N; ++i) {
			for (int j = 0; j < M * N; ++j) {
				System.out.print(mx[i][j] + " ");
			}
			System.out.print(v[i]);
			System.out.println();
		}
	}

	static void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}
}