#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define CHMIN(a,b) a=min((a),(b))
#define CHMAX(a,b) a=max((a),(b))

// mod
const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD

// floating
typedef double Real;
const Real EPS = 1e-11;
#define EQ0(x) (abs(x)<EPS)
#define EQ(a,b) (abs(a-b)<EPS)
typedef complex<Real> P;

int m,n;

typedef bitset<64> bit;

#define ID(i,j) ((i)*n+(j))

void flip(bit &a,int y,int x){
  FOR(dy,-1,2)FOR(dx,-1,2){
    int ny=y+dy;
    int nx=x+dx;
    if(ny>=0 && nx>=0 && ny<m && nx<n){
      if(a[ID(ny,nx)])a.reset(ID(ny,nx));
      else a.set(ID(ny,nx));
    }
  }
}

int dfs(bit a,int dan){
  if(dan==m){
    if(a.count()==0){
      return 0;
    }else{
      return 1252525252;
    }
  }
  // first flip
  int bcnt = 1;
  bit b = a;
  flip(b,dan,0);
  FOR(i,1,n)if(b[ID(dan-1,i-1)]){
    flip(b,dan,i);
    bcnt++;
  }
  // not flip
  int ccnt = 0;
  bit c = a;
  FOR(i,1,n)if(c[ID(dan-1,i-1)]){
    flip(c,dan,i);
    ccnt++;
  }
  return min(dfs(b,dan+1)+bcnt,dfs(c,dan+1)+ccnt);
}

int main(){
  scanf("%d%d",&m,&n);
  bit origin;
  REP(i,m)REP(j,n){
    int x;
    scanf("%d",&x);
    if(x==1)origin.set(ID(i,j));
  }
  int mn = 830252521;
  REP(msk,1<<n){
    int ans = 0;
    bit a = origin;
    REP(i,n)if((msk>>i)&1){
      ans++;
      flip(a,0,i);
    }
    int bef = mn;
    CHMIN(mn,ans+dfs(a,1));
  }
  if(mn>n*m){
    puts("Impossible");
  }else{
    printf("%d\n",mn);
  }
  return 0;
}