#include <stdio.h>

#define FIN "flip.in"
#define FOUT "flip.out"
#define MAX_N 16

int A[MAX_N][MAX_N];

int main(void)
{
    int i, j, N, M, m, s, S, max = -1, config;

    freopen(FIN, "r", stdin);
    freopen(FOUT, "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 (m = 1 << M, config = 0; config < m; config++)
    {
        for (S = i = 0; i < N; i++, S += abs(s))
            for (j = s = 0; j < M; j++)
                s += (1 << j) & config ? A[i][j] : -A[i][j];
        max = max < S ? S : max;
    }
    
    printf("%d\n", max);
    
    return 0;
}