#include <bits/stdc++.h>
using namespace std;
using i64 = int64_t;
using vi = vector<i64>;
using vvi = vector<vi>;

int m, n;

void flip(vvi& b, int x, int y) {
    for (int dx = -1; dx <= 1; dx++) {
        for (int dy = -1; dy <= 1; dy++) {
            int xx = x + dx;
            int yy = y + dy;
            if (0 <= xx && xx < m && 0 <= yy && yy < n) {
                b[xx][yy] = 1 - b[xx][yy];
            }
        }
    }
}

int main() {
    cin >> m >> n;
    vvi b(m, vi(n));
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            cin >> b[i][j];
        }
    }

    int ans = 1e9;

    for (int i = 0; i < 1 << (m + n - 1); i++) {
        vvi bb(b);
        int cnt = 0;
        for (int j = 0; j < m; j++) {
            if ((i >> j) & 1) {
                cnt++;
                flip(bb, j, 0);
            }
        }
        for (int j = 0; j < n - 1; j++) {
            if ((i >> m + j) & 1) {
                cnt++;
                flip(bb, 0, 1 + j);
            }
        }

        for (int i = 1; i < m; i++) {
            for (int j = 1; j < n; j++) {
                if (bb[i - 1][j - 1]) {
                    cnt++;
                    flip(bb, i, j);
                }
            }
        }

        int ok = 1;
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (bb[i][j]) ok = 0;
            }
        }
        if (ok) {
            ans = min(ans, cnt);
        }
    }

    cout << (ans == 1e9 ? "Impossible" : to_string(ans)) << endl;
}