#include<stdio.h>
int n,m,i,j,p, a[17][17], sum, max, sl;

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

    scanf("%d %d", &n, &m);
    for(i=0; i<n; i++)
        for(j=0; j<m; j++)
            scanf("%d", &a[i][j]);

    for(p=0; p<(1<<m); ++p){
        sum = 0;
        for(i=0; i<n; ++i) {
            sl = 0;
            for(j=0; j<m; ++j)
                if(p&(1<<j)) sl-=a[i][j];
                else sl+=a[i][j];
            sum+=sl>0?sl:-sl;
         }

        if(sum>max) max=sum;
    }

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

    fclose(stdin);
    fclose(stdout);
    return 0;
}