#include <stdio.h>
#include <stdlib.h>
#define MAXN 16

int v[MAXN][MAXN], n, m;
int main(){
    FILE*fi,*fo;
    fi=fopen("flip.in","r");
    fo=fopen("flip.out","w");
    fscanf(fi,"%d%d", &n, &m);
    for(int i=0;i<n;i++)
        for(int j=0;j<m;j++)
            fscanf(fi,"%d", &v[i][j]);
    long long config=0, max=-1000000000000000;
    while(config<2<<(n+m+1)){
        long long sum=0LL;
        for(int i=0;i<n;i++)
            for(int j=0;j<m;j++){
                if(((config>>i)%2+(config>>(n+j))%2)%2==0)
                    sum=sum+1LL*v[i][j];
                else
                    sum=sum-1LL*v[i][j];
                //printf("%d %d %lld %lld\n", i, j, ((config>>i)%2+(config>>(n+j))%2)%2, sum);
            }
        if(sum>max)
            max=sum;
            //printf("%lld %lld\n", config, sum);
        config++;
    }
    fprintf(fo,"%lld", max);
    fclose(fi);
    fclose(fo);
    return 0;
}