#include <bits/stdc++.h>

int a[16][16];

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

    int n, m;
    scanf("%d%d", &n, &m);
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            scanf("%d", &a[i][j]);
    int res = 0;
    for (int mask = 0; mask < (1 << n); ++mask) {
        int cur = 0;
        for (int j = 0; j < m; ++j) {
            int colSum = 0;
            for (int i = 0; i < n; ++i) {
                int sgn = 1;
                if (mask & (1 << i))
                    sgn = -1;
                colSum += a[i][j] * sgn;
            }
            if (colSum < 0)
                colSum = -colSum;
            cur += colSum;
        }
        if (cur > res)
            res = cur;
    }
    printf("%d", res);
    return 0;
}