#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(a);i>=(b);i--)
#define pb push_back
#define pcnt __builtin_popcount
#define show(x) cout<<#x<<" = "<<x<<endl;
#define maxs(x,y) x = max(x,y)
#define mins(x,y) x = min(x,y)
#define fi first
#define se second
#define rng(a) a.begin(),a.end()
#define each(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define sz(x) (int)(x).size()
#define mp make_pair

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vpii;
typedef set<int> si;
typedef pair<ll,ll> pll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pll> vpll;
typedef set<ll> sl;
template<typename T>string join(vector<T>&v)
{stringstream s;FOR(i,0,sz(v))s<<' '<<v[i];return s.str().substr(1);}
ll gcd(ll a,ll b){if(a>b)swap(a,b);for(;a>0;b%=a,swap(a,b));return b;}
int modpow(ll a,ll n,int m){if(a==0)return a;ll p=1;for(;n>0;n/=2,a=a*a%m)if(n&1)p=p*a%m;return(int)p;}
void dout(double d){printf("%.12f\n",d);}

const int iinf = 1e9;
const ll linf = 1e18;
const int mod = 1e9+7;
const double pi = acos(-1);
const double eps = 1e-10;
int m, n, M[9], D[9], c;
vi v;
vpii vv;
int turn(int i){
  int ret = 0;
  FOR(j, 0, n)if(i >> j & 1) ret ^= 7<<j;
  return ret;
}
int search(int g){
  memmove(D, M, sizeof(M));
  int ret = pcnt(g), d = turn(g);
  D[0] ^= d;
  D[1] ^= d;
  FOR(i, 0, m-1){
    bool z = false;
    each(itr, v){
      d = turn(*itr);
      if(((D[i] ^ d) & c) == 0){
        z = true;
        ret += pcnt(*itr);
        D[i] ^= d;
        D[i+1] ^= d;
        D[i+2] ^= d;
        break;
      }
    }
    if(!z)return iinf;
  }
  if(D[m-1] & c){
    return iinf;
  }else{
    return ret;
  }
}
main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> m >> n;
  FOR(i, 0, m)FOR(j, 1, n+1){
    int t;
    cin >> t;
    M[i] += t<<j;
  }
  FOR(i, 0, 1<<n) vv.pb(mp(pcnt(i), i));
  sort(rng(vv));
  each(itr, vv)v.pb(itr->se);
  int ans = iinf;
  c = (1<<(n+1))-2;
  each(itr, v) mins(ans, search(*itr));
  if(ans == iinf){
    cout << "Impossible" << endl;
  }else{
    cout << ans << endl;
  }
  return 0;
}