#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define mt make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int a[8][8];

int ans = INT_MAX;
int M, N;

bool check(int y, int x) {
    if(y > 0 && x > 0 && a[y-1][x-1])return false;
    if(y > 0 && x == N - 1 && a[y - 1][x])return false;
    if(y == M - 1 && x > 0 && a[y][x - 1])return false;
    if(y == M - 1 && x == N - 1 && a[y][x])return false;
    return true;
}

void dfs(int y, int x, int cnt) {
    if(y == M) {
        rep(i, N)rep(j, M)if(a[i][j])return;
        smin(ans, cnt);
        return;
    }
    int ny = y, nx = x + 1;
    if(nx == N) {
        ny = y + 1;
        nx = 0;
    }
    if(check(y,x))dfs(ny, nx, cnt);
    

    for(int yy = max(y - 1, 0); yy < min(M, y + 2); ++yy) {
        for(int xx = max(x - 1, 0); xx < min(N, x + 2); ++xx) {
            a[yy][xx] = 1 - a[yy][xx];
        }
    }
    if(check(y,x))dfs(ny, nx, cnt + 1);
    for(int yy = max(y - 1, 0); yy < min(M, y + 2); ++yy) {
        for(int xx = max(x - 1, 0); xx < min(N, x + 2); ++xx) {
            a[yy][xx] = 1 - a[yy][xx];
        }
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> M >> N;
    rep(i, M)rep(j, N) {
        cin >> a[i][j];
    }
    dfs(0, 0, 0);
    if(ans == INT_MAX) {
        cout << "Impossible" << endl;
    } else {
        cout << ans << endl;
    }
}