#include<bits/stdc++.h>

using namespace std;
typedef unsigned int uint;
typedef long long int ll;
typedef unsigned long long int ull;

#define debugv(v) printf("L%d %s => ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;
#define debugm(m) printf("L%d %s is..\n",__LINE__,#m);for(auto v:m){for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) printf("L%d %s is => ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;
#define debugaa(m,w,h) printf("L%d %s is..\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[x][y]<<" ";}cout<<endl;}
#define debugaar(m,w,h) printf("L%d %s is..\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}
#define ALL(v) (v).begin(),(v).end()
#define BIGINT 0x0FFFFFFF
#define E107 1000000007
void printbit(int u){if(u==0)cout<<0;else{int s=0,k=0;for(;0<u;u>>=1,k++)s=(s<<1)|(u&1);for(;0<k--;s>>=1)cout<<(s&1);}}

#define TIME chrono::system_clock::now()
#define MILLISEC(t) (chrono::duration_cast<chrono::milliseconds>(t).count())

template<typename T1,typename T2>
ostream& operator <<(ostream &o,const pair<T1,T2> p){o<<"("<<p.first<<":"<<p.second<<")";return o;}

int width,height;
int m,n;

int field[100];

int main(){
    int i,j,k;
    int x,y,a,b;
    
    cin >> height >> width;
    
    n = height*width;
    
    vector<valarray<int>> mat_s(n);
    valarray<int> vec_r(n);
    
    for (i=0;i<n;i++){
        mat_s[i].resize(n);
    }
    
    for (i=0;i<n;i++){
        cin >> vec_r [i];
        field[i] = vec_r[i];
    }
    
    for (i=0;i<n;i++){
        x=i%width;
        y=i/width;
        for (a=-1+(x==0);a<=1-(x==width-1);a++){
            for (b=-1+(y==0);b<=1-(y==height-1);b++){
                mat_s[i][x+a+(y+b)*width]=1;
            }
        }
        mat_s[x+y][i];
    }
    
    //debugaar(mat_s,n,n)
    
    for (i=0;i<n;i++){// yoko
        // pivot
        if (mat_s[i][i]==0){
            for (j=i+1;j<n;j++){
                if (mat_s[j][i]==1){
                    mat_s[j].swap(mat_s[i]);
                    //mat_r[j].swap(mat_r[i]);
                    swap(vec_r[i],vec_r[j]);
                    break;
                }
            }
        }
        for (j=0;j<n;j++){ // tate
            if (i==j) continue;
            if (mat_s[j][i]==0) continue;
            mat_s[j]^=mat_s[i];
            vec_r[j]^=vec_r[i];
        }
    }
    
    //debugaar(mat_s,n,n)
    //debugv(vec_r)
    valarray<int> vec_r_c=vec_r;
    
    for (i=0;i<n;i++){
        if (vec_r_c[i]) continue;
        k=0;
        for(j=0;j<n;j++){
            k|=mat_s[i][j];
        }
        if (k==0){
            for (j=0;j<i;j++){
               if (mat_s[j][i] && !vec_r_c[j]) goto l_nxt; 
            }
            vec_r[i]=1;
            for (j=0;j<i;j++){
               if (mat_s[j][i] && vec_r_c[j]) vec_r[j]^=1;
            }
        }
        l_nxt:;
    }
    //debugv(vec_r)
    
    // checker
    int result=0;
    for (i=0;i<n;i++){
        if (vec_r[i]){
            result+=vec_r[i];
            
            x = i%width;
            y = i/width;
            
            for (a=-1+(x==0);a<=1-(x==width-1);a++){
                for (b=-1+(y==0);b<=1-(y==height-1);b++){
                    field[x+a+(y+b)*width]^=1;
                }
            }
        }
    }
    
    for (i=0;i<n;i++){
        if (field[i]){
            cout << "Impossible" << endl;
            return 0;
        }
    }
    
    cout << result << endl;
    

    return 0;
}