#include <cstdio>
#define NMax 18

int a[NMax][NMax];
int col[NMax];
int lin[NMax];
int v[NMax];

int main(){
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);


    int i,j,n,m,ans,temp,first,column;

    scanf("%d %d",&n,&m);
    for( i = 1; i <= n; ++i )
        for( j = 1; j <= m; ++j ) scanf("%d",&a[i][j]);

    for( first = 0, i = 1; i <= n; ++i )
        for( j = 1; j <= m; ++j )
        {
            lin[i] += a[i][j];
            col[j] += a[i][j];
            first += a[i][j];
        }

    ans = first;
    while(1)
    {
        // testam configuratia curenta
        temp = first;
        for( i = 1; i <= n; ++i )
        if( v[i] ) temp = temp - 2*lin[i];

        for( j = 1; j <= m; ++j )
        {
            column = (-2)*col[j];
            for( i = 1; i <= n; ++i )
            if( v[i] ) column += 4*a[i][j];

            if( column > 0 ) temp = temp + column;
        }

        if( temp > ans ) ans = temp;

        // next
        for( i = n; i >= 1 && v[i]; --i ) v[i] = 0;
        if( i < 1 ) break;
        v[i] = 1;
    }


    printf("%d\n",ans);


return 0;
}