#include "bits/stdc++.h"
using namespace std;
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
static const int INF = 0x3f3f3f3f; static const long long INFL = 0x3f3f3f3f3f3f3f3fLL;
typedef vector<int> vi; typedef pair<int, int> pii; typedef vector<pair<int, int> > vpii; typedef long long ll;
template<typename T, typename U> static void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> static void amax(T &x, U y) { if(x < y) x = y; }

int main() {
	int H; int W;
	while(~scanf("%d%d", &H, &W)) {
		vector<vector<int> > A(H, vector<int>(W));
		for(int i = 0; i < H; ++ i) for(int j = 0; j < W; ++ j)
			scanf("%d", &A[i][j]);
		int ans = INF;
		vector<vector<int>> flipped(H, vector<int>(W));
		rep(s, 1 << (H + W - 1)) {
			rep(i, H)
				flipped[i][0] = s >> i & 1;
			rep(j, W - 1)
				flipped[0][1 + j] = s >> (H + j) & 1;
			bool ok = true;
			rer(i, 1, H) rer(j, 1, W) {
				int x = A[i - 1][j - 1];
				rer(dy, -1, 1) rer(dx, -1, 1) if(!(dy == 1 && dx == 1)) {
					int yy = i - 1 + dy, xx = j - 1 + dx;
					if(0 <= yy && yy < H && 0 <= xx && xx < W)
						x ^= flipped[yy][xx];
				}
				if(i >= H || j >= W)
					ok &= x == 0;
				else 
					flipped[i][j] = x;
			}
			if(ok) {
				int cnt = 0;
				rep(i, H) rep(j, W)
					cnt += flipped[i][j];
				amin(ans, cnt);
			}
		}
		if(ans == INF)
			puts("Impossible");
		else
			printf("%d\n", ans);
	}
	return 0;
}