#define _CRT_SECURE_NO_WARNINGS
#include<sstream>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<climits>
#include<cmath>
#include<string>
#include<vector>
#include<set>
#include<map>
#include<queue>
#include<numeric>
#include<functional>
#include<algorithm>
#include<bitset>
#include<tuple>
#include<unordered_set>
#include<unordered_map>
#include<random>
using namespace std;
#define INF (1<<29)
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define uniq(v) v.erase(unique(all(v)),v.end())



int n, m;
int b[8][8];

int dy[] = { 0,-1,0,1,0 ,1,1,-1,-1 };
int dx[] = { 0,0,-1,0,1 ,1,-1,1,-1 };

void put(int y,int x,int a[][8]) {
	rep(k, 9) {
		int ny = y + dy[k];
		int nx = x + dx[k];
		if (0 <= nx&&nx<m && 0 <= ny&&ny<n) {
			a[ny][nx] ^= 1;
		}
	}
}


int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	cin >> n >> m;
	rep(i,n) {
		rep(j, m) {
			cin >> b[i][j];
		}
	}


	int ans = INF;
	rep(i, 1 << n+m - 1) {
		int c[8][8];
		memcpy(c, b, sizeof(c));
		int cnt = 0;
		rep(j, n+m-1) if(i>>j&1){
			cnt++;
			if (j < m)put(0, j, c);
			else put(j - m + 1, 0, c);
		}
		rep(y, n-1)rep(x,m-1)if(c[y][x]) {
			cnt++;
			put(y + 1, x + 1, c);
		}
		bool ok = true;
		rep(y, n)rep(x, m)if (c[y][x])ok = false;
		if (ok)ans = min(ans, cnt);
	}

	if (ans == INF)cout << "Impossible" << endl;
	else cout << ans << endl;

	return 0;
}